Yes, one can photograph the pueblo without paying to go onto the grounds, but evolved people don't out of respect for the culture. If you don't get that, then don't go.
As to O'Keefe's house, you will find it in Abiquiu. Quite a bit more distant than 50 miles. Lots to do in Taos, but you have to be willing to give up your apparent need for strip malls and big box stores. I could list them all, but since so many folk are just too plain lazy to discover things for themselves, I won't offer my considerable legwork.
Santa Fe pretentious? Sure, if you say so. But if you really feel the need to compare Taos with SF, then the pretentiousness you speak of might be more clearly found in your mirror.
Excellent galleries in both cities, fascinating histories, and when visiting Indian dwellings and reservations, remember to show a little respect.