1) I'd suggest the last weekend in April or first weekend in May. Alternately, some weekend in early July, well enough before Osh Kosh.
2) Yes, a 3-day weekend as you said
3) Personally, I'll probably want to do motel, especially after that many hours on the Interceptor. It ain't a Goldwing.
4) I'd definitely want to have as many meals as a group as possible. Preferably Friday dinner, Saturday all meals, and maybe a Sunday breakfast before heading home.
5) I'm not sure how many people we think we'll have, but I'm used to going on rides of 10-50. I'm thinking we'd have 20 bikes or so. If there are some people who want to blast ahead, sure, but I'm used to just being as a large group. If anything, I'd lag behind when someone else had to stop, and then ride faster to catch up with the rest of the group after solving the person's problem.
Besides, I've generally thought it's good to keep riders of less skill with riders of higher skill.
6) Well, location is the main one. I know you suggested your area, which is fine by me, but we've also got people coming from different areas that might be too far. So, it might be worth people suggesting alternate locations, and seeing which would gather the most? I, for one, would volunteer my area of Williamsport, which is a great place to ride, but I don't think that helps the people west of the Mississippi any.