One place to start is contacting the department directly and asking to speak to current students. I just got done with 8 years of school and often talked with prospective students. Seriously, it's the best way to get a feel for the department.
As for scholarships, I would imagine it depends on what the specifics of your scholarship stipulate. Some may transfer, some may not. Again, the best place to start that would be the scholarship website itself, or the scholarship office at UH. They deal specifically in that, so they may be able to even connect you to someone who would know exactly. I can't say my friend.
As for programs and difficulty, again, I just got done with 8 years of school among a few different schools (I'm a medical specialist) and can say that there's really no real 'equation' for admittance. I worked on one admittance board (tangentially) and can say that each year things change as the faculty who rotate in and out of the admittance 'team'. Even in smaller departments (linguistics, humanities, etc), there is usually this rotation. So one year, they may be looking for higher grades, while another year may find a different faculty member on the admittance team looking for higher references. It's really hard to say.
Again, talking to the department directly would help answer some things, though they will most likely give you some broad answers for some of your questions
Do not be afraid to talk to anyone in the department - they are there to help! Both current students and prospective students (like yourself). Find your voice and ask your questions - it is the only way to start to find answers!