So if I purchase a Convention 3-Day Park Hopper Ticket for $175 I can use these as regular tickets? You do not have to be a part of the convention?
That's how I understand it, and I sure hope so, because a ton of us DISers purchased them! The only downside is you don't get any early entry privileges with the convention tickets, so you won't get Magic Morning or anything like that. Just the regular park hours, which should be fine for the time you are going. Just be sure to arrive at rope drop and you'll be fine.
For the dining, I know Get Away Today does offer some vouchers, but I've never used them. I think they are a decent deal on character dining, because they include the tax and tip, but again, I haven't used them so can't be sure.
Dining is NOT like at WDW, so you don't have to stress about reservations. You should call for the most popular spots (Blue Bayou, Carthay Circle, character meals) now, but for the most part you can make ressies the day of. Also, I think DLR does a better job with quick service dining in many cases, so you don't NEED to eat table service as often to get away from burgers, etc.
Just my opinion, but hopefully that will help you out! You picked a great time to visit, we go in October every year!