[@shylarah]
Yes, anything goes in terms of characters; even if they can't normally coexist. Just as an example; if you want to get two characters that are the two sides of one character to run around, that's fine.

As for posting, it's the latter. The 'hours' are just ways to add some structure to the RP. During the hours you'll be able to do whatever you like, and when I say 'declaring' at the end of the hour, I mean that in a sense where you're essentially saying you're done for that block of time, and would like the general story to progress.