1. Yes
2. I'm pretty sure I've read that it is in, but to tell you the truth, I haven't tried it myself lol. I'll do so tonight.
3. Yes, but 5 on one computer will require a rediculously powerful comp. I recommend 8GB Ram minimum for 5 instances. Someone did post a little while ago and was able to load 3 instances on a Q9450, so at least we know there is no limit similar to what DAoC had.