These are questions your architect should address. Are your questions regarding appearance (style) or operations? Regarding ceiling fans, that depends on where you are. In my new build in northern NY, I had the wiring for ceiling fans in all the main floor rooms, but, so far, have only installed one in the master bedroom. We don't have central air conditioning.

I think you're right about more lights are better, especially in unfinished basements and attics. A bare bulb in the middle of one of those spaces means remembering to bring a flashlight every time you go to look for something. I have owned just three smallish older homes with small rooms and all needed extensive renovations. I like surface mounted fixtures in living rooms, dining rooms, and bedrooms. It just took one one fixture to light up most of the space and the furniture locations won't change much. Table or floor lamps can supplement areas that seem to need more light. None of my ceilings are high.

Recessed lights in kitchens have worked out well for me, but it takes a lot of fixtures to to get all the light you will need or want.

Ceiling fans in bedrooms are a definite "yes", in living rooms they are a "maybe". It depends on the height of the ceiling, and the height of the tallest person who will ever enter your house.

I can offer no advice on the last two bullets.

Dimmers everywhere. Think about receptacles in cabinets, not just for master vanity but where gadgets like routers or tv components will be located. We put an outlet in the fireplace mantel, for both Christmas lights or if someone in the future wanted to put the tv over the fireplace.Receptacles in cabinets for stereo components.

In the bathroom, think about how you use the sink area. We forgot, so the outlet for the sink is on the left side for my right handed DH. Very inconvenient because the cord for razor, etc, has to drape across the sink.

Receptacles in the toilet area by the toilet in case in future you want an automatic seat washer/dryer; and/or, to have a place for a night light.

Think about where you are going to put: routers, printers, small appliances, phone chargers, etc...

If you have a porch, receptacles on the porch for lamps/fans/tv etc.

Tiny led lights under stair treads are useful, make sure there is a power source nearby with a switch.

In our bedrooms, we put small 4" cans in the corners for general lighting, then a ceiling fan capable box in the center. Some rooms have fans, some have the central light; but they all have the capability for the fan.

Receptacle on exterior for holiday lighting.

:) Hope that helps.

Designing during a walk-through, meaning definitely after framing and probably with rough-in electrical started or finished, is not the time to be determining light locations and styles. More info needed.

I'm also confused about whether this is in the design phase or the walk-through phase.

Hopefully you have designed all the elements into the plans or you will find these potential add-ons quite expensive. You really have to think out how you live in these spaces.

Our build is in Florida, so we have ceiling fans in almost every room.

Bathrooms: We have vent (exhaust?) fans over every toilet. I wanted those light up mirrors, but I don't think the electrical was done for that. We'll end up with standard over mirror vanity lights. Be sure there is an outlet for a bidet if you are doing an accessible bathroom. Lights in the showers because I hate dark showers.

Kitchen: We have a giant vent hood over the powerful gas cooktop. Can lights at the specified distance apart and away from the cabinets, light over the sink, under cabinet lights, in-cabinet lights for the glass fronts, and pendants over the island bar. Lots of switches in the kitchen, and a lot of outlets to plug in appliances, I think every 12-18".

Exterior patios: ceiling fans and lights controlled from inside. Also had switched high-mounted outlets for Christmas lights or string lights. And a spotlight for a wall which was have art on it.

Other exterior: light walkways, dark corners, think about security and bad guys not being able to hide (but thats landscaping too)

Big rooms: tend to have paths leading in/out/through, so think about multi-switched outlets at each end, etc depending on your expected use.

Media: Put an outlet smack in the middle where the TV/monitors will go. Where will the routers go and where to run RG45 or Cat6, etc. We have junction boxes with all the cable or ethernet lines running to the routers and TV locations. Security cameras. Lots of electronics to think about.

Good luck!

As far as switches go through your rooms like you are walking into them in the dark to flip on a light. Keep in mind the way doors swing. Never put a switch behind a door. In a bathroom be sure you have two switches on the same plate. One for the overhead light and one for the vanity or sconce light. Mark areas you want to be able to enter and leave a room for four way switches!

First time home builder not likely using architect or doing custom.

Tract builders often have walk throughs at framing and this is likely the scenario.

Options are available at a cost at this point. The cost is generally high but often worth it. Usually, adding cans to a bedroom is (at this point) not a wise use of money since the cost will be high.

My advice - go armed with the cost of add-ons. Also go with some idea of how difficult and expensive things would be to do later - ie after closing.

With the upcharge in tract homes, one of the few things I would add is an outlet in large closets or pantry. These are not code but are very helpful.

Router location also.

I would not pay the high prices for LV wiring generally.

I find ceiling fans in living rooms to be not needed and generally less aesthetic pleasing than a chandelier.

Can lights are popular because they require no imagination or design sense. They are also relatively cheap - but add up because you need so many of them. Good for cleaning in a bedroom but not much else (IMO).