We went when our youngest was 2.5. We also had trips when each of the other two were 3.5 and one trip when one was 3.0. We always had at least one child though, but found the 2-3 year old of the moment dictated our plans. We've tried going back to the room to rest/nap and it has never worked - with any of the kids. It just wasted time. As for napping in the park, that hasn't worked the greatest for us either. The 2.5 year old did occasionally fall asleep, but only in my arms. I've seen other kids sleep in strollers, so I know it's quite common, but none of my three have ever slept in a stroller. I brought a stroller from home so it would be more comfortable. Plus, it's cheaper that way! My kids weren't used the stroller though, so the trip with a 2.5 year old resulted with the child being carried in a sling. We were able to bribe that child at 3.5 years old to sit in the stroller though. (My other two kids did sit in the stroller some at 3 years old though).
We generally plan zero table service meals. I'm on vacation and two of my kids at table service were not very vacation-like. The other one could have handled it easily though - so it comes down to you knowing your child. We always hit rope drop. And then go until someone acts like it's time to leave. I can't make my kids naps. But I can get them in bed in plenty of time and rely on that. For us, tired kids is not fun on vacation. My eldest could always roll with it, but my middle child absolutely cannot - even now at 7. So, we focus on bedtimes at night and learned to not worry about if/when naps happened. As for table service, we are bigger into the rides/attractions and don't want to take the time for the table service, especially if kids may not behave. That gives us more flexibility and more time. We might get a rotisserie chicken from the grocery store and eat in our room, or go by Sweet Tomatoes (a buffet), or eat in the parks. We never know if we're going to make it through the dinner hour so we like not having our dinners planned out. Lunch gets in the way of our precious park time so we like fast counter service for that.
I second the Epcot suggestion. We weren't very optimistic many years ago, when my oldest was barely 3 (and a 2 month old, but she was just along for the ride!) We had never been to Disney with kids and didn't think Epcot was geared towards kids. We were very wrong. Epcot was the favorite park of all three for quite a while. (Actually, for every child, every trip except I think HS may now be slightly in the lead for my 10 year old).
I also strongly agree with the snack suggestion. Sometimes they need a snack and they need it right that second. It will save you money to bring some snacks - but it will also save some meltdowns.
If your child is toilet trained, consider bringing sticky notes for the bathroom. They have automatic toilets and those scare some kids. Just put a sticky note over the sensor, and the child won't worry about it flushing while they're still going.
