Rice is a generally reputable school, although I'm not familiar enough personally to say any more than that, and a full-tuition waiver is nothing to scoff at, but you should also think about the living expenses if there's no stipend attached.

I can say a little about Houston - the amount you'd have to pay me to live there for 3½ years is a LOT more than a full ride at Rice. It's hot and humid most of the year, punctuated by occasional hurricanes, and, even worse than the weather, it's full of TEXANS!!!

Hi! I'm currently in the 3.5 year masters at Rice. I'll do my best to answer your questions, but feel free to DM me if you want to talk further.

1. This was something I wondered about before attending as well. I didn't overlap with her, so I can't really speak to this firsthand, She seems to have had a lasting impact on the program's reputation (I've heard that getting the school to rank well was a big priority of hers), but it seems like other faculty are kind of relieved by her being gone because they can reclaim some autonomy. That's all I can really say there. The new dean is a little too new to have done much, but he seems to be extremely compassionate and socially-minded.

2. Theory does tend to pervade through everything at Rice, even though our studio briefs are often more practical programs. The first semester theory class is excellent, but the subsequent ones not so much. That being said, I've found that the theory you're exposed to through studio readings and discussions is most productive anyways. 

3. Most grad students have no interest in staying in Houston, so you certainly won't be alone on this front. Rice alumni end up all over the country. A lot of the research and courses do focus on Houston since we're here, and since it's a pretty fascinating case study for a weird kind of (non)urbanism. But even that content isn't too specific to Houston--it will be relevant elsewhere too. The new dean keeps talking about globalism as a key interest and focus, so I would guess that the school will be broadening its horizons more than narrowing them.

4.  I'm not an international student, so I can't speak directly to this, but I can say that Houston is an incredibly diverse city (the most diverse in America according to some metrics) with a huge international community. There are lots of international students at Rice Architecture, and the broader university has social programs for international students, so you'll have an instant network. Rice is in a very safe part of town. 

Hope this helps!