I have no need or desire to be able to enter every single building in BG. We should be able to enter (many of) the public buildings - shops, inns, churches, jails, etc- but aside from those, only the houses that contain quest-relevant people/items should to be accessible.
I think I'd also prefer if BG was split up into different maps you can fast travel between rather than a single continuous map. In the case of a single map, either 1.) an underwhelmingly small BG will result in areas that should have distinct atmospheres being crammed too close together, or 2.) an appropriately large BG won't be very fun to navigate. While walking around Novigrad in TW3 is very immersive due to the perspective/single PC/control scheme, walking through a humongous city in BG3 will be more of a point->click->wait tedium.
