I’m not a tech writer, but I work for a software company, so I might be able to answer some of your questions. I’ve found that they hire people with a English/Journalism degree, pretty much anything proving you have the ability to write. Working from home is a privilege that you earn, but it’s different between companies, most in tech don’t care and it’s very common. I’d imagine the career is on the rise, as tech isn’t going to be going away. Not sure what the outlook is in different spaces, but I think it would be similar.