They all look fine and healthy to me. Plain potting soil is fine as long as it doesn't have a huge amount of peat in it. Yours looks grand. When they get bigger and there is more warmth and light, you could repot into a grittier mix if you like. I think we fuss too much over soil. If it's draining well and they are not overwatered, they will be grand.

As for ID, can you post individual pictures to show them better. I think I see a Peperomia (yellow), Sedum rubrotinctum (red), a Senecio (pink), and maybe a Crassula ovata 'Gollum' (blue).

Thank yooou :) ok, I will take better shots this evening and post them tomorrow the latest :) have a nice afternoon!

Blue square is crassus muscosa or "watch chain"plant

Oh, color-coded! I couldn't tell on my phone. The orange box looks like an etiolated titanopsis.

For better ID, we really need bigger photos, or we are only guesing. Try to get them larger and clear, and either color-coded as they are or numbered. Thank you.

Orange: Titanopsis calcarea

Green: Kalanchoe tomentosa

Pink: Senecio serpens?

Yellow: Peperomia graveolens?

Good morning! Spring is here! (At least where I'm at :)) )
Here are the enlarged photos. I guess we can just number them by order. Thank you!

And here are the rest:

And this one, I just want to ask what's wrong with it. The lower layers are dying. I have it for 6months almost and it grows very slowly. It has sun and is in a shallow pot with regular potting soil and I don't overwater it. I have other succulents in that same pot and they're fine.

The above is a Sempervivum Arachnoideum. Whenever my Semps look like this they usually have mealy bugs. I'm not saying you have them, but check the stem and in between the leaves. Could just be old leaves that need to be cleaned up. Do a Google image check just so you can see what this bug looks like. If you're getting into succulents it's probably best to know what kind of pests these plants get. Mealy bugs are the devil;)!

These plants do better in bright light/shade than sunlight. At least in my experience. If mine get to much sun they start closing up real tight and dry out. They also start to slow down growth when getting too much sun.

The pic above your Semp is a Pleiospilos Nelii:)

Pic below Kalanchoe Toementosa is Kalanchoe millotii

Purple box is an Echeveria of some type

Dismiss my guess for the blue square. Chris is correct for ID on the Watch Chain, Crassula muscosa. The one below its picture is Pleiospilos nelii.

Ps. My comment just showed up. Houzz is still having problem with post, I guess.

Not to dismiss what Kara said about possibility of mealy or other bugs on sempervivum, but there is a chance of it being growing conditions: semps are hardy plants and best grown outside year round. I am not sure if you mentioned your general location/zone (best if added to your name), but they survive outdoors in z4 and even z3. I grow lots of them outdoors. Never had mealy bugs on them. They would do very well in fast draining mix - as all other succulents.

Pepperomia may be P. dolabriformis?

You are lucky Rina. I have such a hard time keeping meallies off my Semps. It's crazy! I just had to throw away an old semp. It had so many mealies on it. I wasn't willing to waste my time or energy to get rid of them. It's definatly my hardest plant to keep them off of. I don't even know how they got on it. This was in a pot all by its lonesome far away from anything else. From now on I guess when I get a new one I will have to instantly use a systemic.

Kara

I am sure it is more humidity you have in your location. As you know, they are alpines and do not care for much humidity & high temps. Sure, yo can grow them but they are bit fussier than here. Mine are just uncovered from well over 2-3' of snow and look surprisingly good (these are in4" pots):

But, I can't grow many others as well as you do, lol...and have to worry about etiolaion for almost half a year ): while indoors for winter.

Thank you Rina and Kara.

I have an idiotic question. Since English is my second language... I'm not sure I understand exactly what a "hardy plant" is. I can understand it in many ways and don't want to get it wrong :)

I live in Central Eastern Europe, we had -20 degrees C for about 2 weeks in total this winter and a lot of frost, snow and low light. And in summertime we have even 40 degrees C.

Anamaria

Not an 'idiotic question' at all.

Hardy means that they will survive freezing temperatures (exact temperatures vary some from plant to plant). In case of sempervivums, they are alpine plants. I come from Europe too, and remember them growing all over the mountains...Where I live now, in Ontario, Canada, winter temps get down to below 20C for longer than 2 weeks :). It will be warm enough to take typical succulents outdoors sometimes in May (most of the ones you have in photos). But sempervivums - common name Hens & chicks - stay alive outdoors year long. As long as they have good drainage, they will live under snow and cold temps, some as much as around -35C (z4, even z3). There are few that are hardy only to z 5, but not that many.

Omg, really? That's amazing! So I can try to plant Sempervivums outside! :D I had no idea, you don't see them in our country/mountains (Romania/Carpathians), so I was under the impression that all succulents need warm climates and especially no snow/frost. I'll try that out this year :D I'll plant some in May/June, as you said.

Anamaria

You probably just didn't notice them. From what I know, they grow in wild in your country, and just about all of the Europe. Check this site for locations in Romania

-click here please-.

You'll find photos of sempervivums that grow there, in wild (there are about 50 species and few thousands of named cultivars) and maps/locations. I think you could put yours outside earlier than May (that is the time I take other succulents outside - ones that could not survive the winter). Just make sure they are potted in well draining mix.

(In that article, vermiculite is mentioned as a suitable ingredient. Most of us do not use it as it deteriorates quite fast. In containers, sand could create problems if it is fine. I use mix of chicken grit -bought in farm supplies store- and perlite and add some turface. You don't need to go crazy looking for the ingredients, just make sure that containers do not contain very fine soil that compacts. These plants will grow easy in the garden, planted directly in the ground. They look nice in rockeries .)

There are many sites with many photos of different semps, one example -is here-

Hi! Me again. With a problem I noticed on one of my cacti. I don't know the name of this one either.
I noticed it has some black spots. I tried to remove them with a toothpick, but they are extremely well stuck. I suppose they're some kind of bug, right? :( there's more than a week ago.
What can I do?

Thanks!

Can't tell if they are bugs for sure but I do not think so (photo is not sharp enough for me to tell - maybe someone else can see better). Scale looks similar, but it is usually more brownish color, not so dark black. Test if bugs: take a q-tip or cotton ball. Moisten with rubbing alcohol. Wipe over the spot - if living creatures, alcohol should 'kill' them and they will come off. You shouldn't have to rub much.

Spots look more as scabbed-over mechanical damage. Is it possible that something was poking the plant? Some insects could be chewing holes and holes could scab over, but you would probably notice earlier.

Ok, Rina, I will do the alcohol test. I don't remember seeing the black marks when I bought it two months ago, but it could have been poked during transportation from the shop.
My mom asks, if sempervivums can survive outside year long, can they stay in direct sunlight in summer or do they need shade? It gets up to 30C in shade, so much warmer in sunlight.

I keep them in full sun, but we don't get many days of 30C and higher...for very hot areas, it is recommended to give them some shade. Location with sun until about noon and then dappled or partial shade should work well. If you don't have suitable spot, putting a large plant in front to create some dappled shade will work very well. I would not grow them in total shade whole day long. They should be also in a spot that gets good air circulation.

They are sold with labels suggesting growing zone 3 to 10: US growing zone 10 is supposedly up to 40C. Some member here from those hot areas posted before having bit of a problem with sempervivums unless they give them some shade. Humidity seems to be a problem - but that goes for most succulents.

In winter, make sure they are not in a low spot where water could accumulate.

I was working with a customer in the greenhouse the other day and she was picking out a succulent plant when she noticed something sticking out of one of the stems, she thought it was some kind of spider or bug but upon closer inspection I could see that the stem had been scratched and the injury site was sprouting roots, it looked very similar to this, it even looks like there might be a little root coming out on your picture.

I just got this one myself and believe it is Peperomia dolabriformis