It depends on the state; my assumption is that if the state recognizes your union, there's a good chance that you can adopt, but I don't have any solid info to back that up.
I have heard of people in Florida (where gay marriage isn't recognized) where one partner jointly adopted the biological child of their partner. Whether this is allowed seems to vary from county to county (or even from judge to judge).
I don't think you can. You either has to be single or married to adopt. Just living together is neither. if you are in a samesex relationship and has gone through partnership might be possible though.
Anyone can do anything they want to as long as they truly want it. No, in Islam having a boyfriend/girlfriend type of relationship is not allowed whether your a male or a female and whether the bf/gf is Muslim or not. If you have anymore questions regarding the matter, just ask and I'll be happy to answer them. i gree in islam having a boyfrnd or a grlfrnd is not allowd but today no youngr generation follows it .....so if a muslim girl personlly like a non muslim boy...then it is not allowd in islam.....u cannot marry him unless he accpts islam...:)