I did write a huge text and accidentally closed the window and wasn't able to recover it, so here's a little resume of what i've wrote before:
I think you should balance both options and consider some aspects:
The houses with small rooms and living areas, kitchens, etc. have less SQM to put your stuff into. And i believe that the main purpose (for the players, of course) of having a house is to showoff. So, less SQM means "less places to put my stuff", and that's a con. In other hand, they're "more roleplaying", i mean, they're more realistic, cuz' most houses do have small rooms and living areas, that's a pro.
The houses without those small rooms are very good for showing off your accomplishments and achievements in items or whatever it is. That's a pro. But they look like a big square studio or something.
Conclusion: As for the big studios the main purpose is showing off, what place is better for doing so than the main city square? And if it is a city, i think that the houses with the small rooms should be more secluded, in "Residential" areas (well, I do not know how your mapping is, and i don't know if you have those residential areas, but when i, for instance, made an OTS, i used to focus on roleplaying, and we do know that most cities, mainly those "organized medieval" have those areas).
Obs: There's a lot of variables to be considered to this, but these are some solid arguments.
For this i have both an opinion as a suggestion:
Well, the counter direct to the street is a very cool feature, i believe, but there's this big con, that is all the thrash thrown directly into the houses, and there's nothing nobody can do about it.
So, what if, we could control some areas of our houses to be public and others don't? I beliece it's no hard to make a system in which i can select who can enter certain room in the house (or at least, who can open and close doors). Knowing so, it would be no hard too to make house owners to be able to make their houses public.
I'll give an example and explain why doing so: Imagine that i bought this house:
And, let's divide the rooms into A
So, let's assume that I, as the house owner, can control who can or cannot enter each room - or easier, who can or cannot control the doors.
With that authority, I could have a very functional shop.
How? I could make room B
public, but not the room A
(and only I could control the doors, that means that I could open and close the shop whenever I want to), or I could make all the house public (anyone can enter it - actually it could be a nice feature for hosting parties in any house), but only selected could control the doors. That means that i could put all the items in room A, and everyone could enter the shop whenever i make it open. It would bring you really more control over your houses, meaning that you could use them whenever and however you want to.
3 and 4.
Before i'd make a large text explaining about how it depends on each taste and how you should balance the two options based on your own "mapper" and "roleplayer" as much as "architect" instinct, and let the options balanced. But i guess that's the function of this survey, right?
That's a really nice question, and it's really hard to give an answer, cuz' it's a very personal idea. All of them should exist, and each one choose the one more convenient for themselves.
If anything was difficult to understand, ask that i will explain it better. Thank you for your attention, and good luck on mapping, I do know how difficult it is to map with real roleplay input.