Please get a tiling contractor to do your shower. It is obvious from your questions that this project would be too much for you without alot of instruction that this forum could not deliver. Could you hire a contractor as a consultant? If you are a quick learner, good at other construction skills and get some very specific advise it may work out. Good luck!

don92, You are right. I am planning to hire a tiling contractor to do it, and tile the living room etc., However, I have spoken with a few tiling contractors and they have provided different solutions. I am so confused and didn't want to do it wrong.

A couple of rules to consider regarding shower construction:

1) You need a minimum of a 2" drop from the shower curb to the shower drain. Meaning that if you were to plug your shower drain, your shower needs to be able to hold a water depth of 2" at the drain while still maintaining it's water-tight integrity, ie, no leaks anywhere.

2) Floor pitch. Min of 1/4" drop per foot, max of 1/2" per foot.

Do those showers you show comply? I have no idea how they fit in to the overall code restrictions, or what code applies, yadda, yadda. I have built showers with floors that appear completely flat to the user, but that requires a bit of work with the building office to get them approved.

Regardless, in my world, to get 2" of water depth at the drain with a 1/4" pitch you'd need to waterproof the floor out 8' from the drain. With 1/2" pitch, 4' from the drain. Those are generic limits. Typically the entire floor would be waterproofed, it's referred to as "wet room" construction.

That's why most showers have a vertical curb at the shower entry, to help achieve

For wet room construction, I'll use mud to slope the floor. Over that I'll use a topical membrane, Kerdi inside the shower area and Ditra with Kerdied seams outside the shower area.

So...

-Yes, your shower is big enough

-30" is better

-Usually not a "pan" as we typically think of pans. More common today is a topical membrane versus a "buried" membrane like CPE. The tile goes right on top of the membrane. Personally I'd use Kerdi/Ditra combo, but that's my opinion. There are other membranes out there.

-Not sure what drain combo they are using. But trench drains are common too, especially at the edges of a walk-in shower. Your first photo I can;t see a drain, it might be a trench. Second photo has a central floor drain, and it might even have trench drains at the edges of the glass.

We had one of these fancy showers in a hotel in Venice, Italy. It had the drain in the floor, no curb, and a curtain. On getting out of the shower, we almost broke our necks because the surrounding floor was splashed. Beware of this hazard!

Another time in France I leaned against the partial shower enclosure which promptly swung open. I nearly lost my balance and fell out. Beware new designs!

We were thinking of this for our shower and are glad we didn't - we like the warmth of the shower with a door, even though our bathroom has a heated floor and new heat ducts. It is always colder outside the shower and now we can towel dry inside the warmth of the shower.

We have a doorless shower that is in a small room with the toilet. Since the area is fairly small, the heat stays in nicely. And this is a case where the smaller shower entrance is better, because it keeps the warm steaminess in the shower better.