There are two scenarios I can think of right now where it would be a good idea to get the dinner package. If you think you want to eat at Wine Country Trattoria anyway, then absolutely get the dining package. Shouldn't be too hard to get booked and I don't think it costs any extra. I've heard that at Carthay Circle they make each person get an entree and either an app or dessert, but I don't know about Trattoria. The second reason to book the dining package is if you don't see yourselves getting to the parks in the morning. I definitely don't think you need to be there right at opening to get the WoC FP, but you're probably going to want to be there in the morning at least. I don't think lunch or dinner matters, but I don't think I'd recommend the picnic lunch; $15 for a cold meal that comes with a FP that you should be able to get for free with minimal effort? Nah.
Here's my experience with WoC back in November. I definitely did not see the lines forming for the WoC FP like I read online that there were when it was brand new... everyone and their mother is in line for the Radiator Springs Racers FP at opening now. As late as 2:30, I was just strolling by and got FP for the only WoC that night. I wouldn't count on it that late by any means, but they won't run out in 30 mins after opening, either. I would get FP for Racers and WoC together first thing in the morning. If the line for the Racers FP is long enough (probably to around Disney Junior), you could even send one person to Racers, one person to WoC and then have the WoC person bring the passes to the person in line for Racers FP after they're done. Did this a couple times. Holding a World of Color FP does not affect your ability to get a FP for a ride.
This is my preferred method of viewing: grab some counter service food and get to the viewing area about 5-10 minutes before it says you can return on your FP. I got there once at the exact time and they were already letting people in, and once I got there five minutes early and I still was not the first person they let into the viewing area. Grab your spot right on the rail all the way down at the bottom and chill. Relax, eat your dinner, gather yourself from the day, etc. I don't think the viewing area is particularly centered for the show; what I think the best spot to watch from is the area around the line that I drew on
this map. I watched the show twice like this and once I got there 20 minutes before the show and was kinda jammed at the back of the viewing area. Still a nice show, but not the
experience it is down in front. The show itself is pretty massive; standing in that area I marked, you almost feel surrounded by the fountains and they can tower over you more than 100 ft in the air. You feel really close to the fountains down in the front, and with no one between you and the show it's an intimate experience. The area I marked is in the red, but I had blue FP's both times and I made it there no trouble. The way the ropes were set up when I was there, the upper sections were separated, but the very bottom right next to the water was all together, red and blue. I'd honestly recommend people wait the full hour for the show even if they only had two days at DLR; since you've got a few more, I'd definitely see the show like this the first time.