I have very little experience with writing for content mills, but I don't know if I would put that much work into a company. Like you said, they could be gone in the next 5-10 years. I'd definitely be weary of giving all of my information to something online like that as well. Especially if they were asking for things that seemed to be TOO much. I remember signing up for a transcription job online and they asked for a lot of information as well that I gave them. So I'm guessing this is the same deal.