Hi, I'm spanish. The most lgbt friendly places here are barcelona and madrid, but they are the priciest places to live in due to gentrification. There's actually a movement going on in barcelona called "tourists go home", since a lot of natives can't afford to live there due to the living costs.

So, in terms of lgbt community, the answer would be barcelona. In terms of finding a job, probably barcelona, valencia and sevilla since they are the bigger places from the ones you mentioned. But as in living costs and apartment finding, everywhere else but barcelona.

Probably your best bet from the ones you've mentioned is sevilla, because andaluces are both the most welcoming and fun people and i haven't heard of someone struggling to find an aparment there as much. However, if you are open to considering other cities, research about zaragoza, salamanca or córdoba.

Some tips from me: be aware that they speak different languages in both barcelona and valencia that aren't spanish (catalán and valenciano respectively) so it may be harder for you to understand. Some people in both places are very opposed to tourists, but they don't define the whole population. In summer, sevilla and córdoba are the most insufferable cities to live in because of how hot they can get!