Multiple hosts are fine, and if it doesn't interfere with your other plans, even just being there would be a great help. And if you can get your Kyouya to host, that would be awesome!
The hotels are pet friendly, I already contacted them and they said I can keep dogs in my room, but if my brother stays home or my mother, then I won't need to bring him. I will contact the Kumoricon staff about it though, because I might bring my husky for my Ember cosplay (if I get it done), she's better mannered and she would love the attention and the exercise. She'd be better for a convention.
I remember the first year I went, a girl was carrying around a puppy with her cosplay. I think it was... Princess mononoke? I don't remember what movie it was but the staff didn't seem to have a problem with it.
Then again, things might change.
I think I'll have to see how big the tables are and how many hosts I will have before I decide on how many guests. But I will send in the forms soon, I'm almost done filling out. (Inner Tamaki finally realized what it was.)
I think 2$ or 3$ or something cheap will be fine, just so that people who are serious about wanting to go in will do it, but those who aren't serious will be filtered out.