I've seen people of all races that are trans not only here, but elsewhere, too! Most of my trans friends are actually POC! I only have maybe two white trans friends, with many more that aren't white. It's just that the white ones tend to get more visibility. :/
As far as porn goes, I think that if the trans actors are okay with it for themselves, then it's alright. But as others have said, if they're doing it because they're in a desperate financial situation or to gain funds for surgery, it's very sad. The word "->-bleeped-<-" is very gross, and a lot of derogatory terms are used for anyone in the porn industry, but it's even worse when it comes to trans actors.
It's absolutely untrue that the trans community is free of hate, because there are always people who hate other people or things. I'm going to admit that I have a lot of hate in me. It's not something I'm proud of, but there are a lot of things that have happened in my life that cause me to hate certain people and groups (pedophiles, abusers, manipulative people, just plain mean people, etc)
I've actually never heard that said about trans people and sexuality, I'd say the most common stereotype that I've heard personally is that all trans people are attracted to the opposite gender, and if they were cis then they'd be gay. For me, I'm sexually attracted to men, but I have a romantic relationship with my girlfriend. I've been told that I could just be a straight girl because I'm attracted to men... But that's not how it works.
Overall, my experiences with the rest of the LGBT population have been pretty okay! I have excellent friends who are LGB but not trans, and I haven't had an issue with them at all. I'd actually go as far to say that I only have two or three straight friends, and the rest are somewhere on the LGBT spectrum! However, I have had very negative experiences with LGB people in the past. I used to go to an LGBT social group for teenagers, and I was one of the two trans people there. Both of us were constantly left out of conversations and mostly ignored when we had anything to say, except by the facilitators. I've been called slurs by some LGB people, and it's just a fact that not everyone sticks together like they say we should.