Depends on the hotel, but generally no more than four. Yes, we've heard of people cramming 10 or more people into a standard double room, but it's unwise and violates your hotel's rental agreement (and the fire code), and they're perfectly within their rights to kick you out, or charge you for the extra people. They are less likely to worry about your extra body or two if you don't make a nuisance of yourself -- so don't put extra demands (towels, pillows, key cards) on the hotel for your extra people. But we encourage you to follow the rules.

All concessions are handled through Centerplate.  Some things like Pocky and Ramune are available at the Centerplate concession stands.

If Anikon's your first convention, expect to be just a bit overwhelmed. There's so much to see, so much to do, you may not know where to start. So try to sample a bit of everything. Just go with the flow, have fun, make friends, and share in the celebration.