The best way to avoid lines it to be in the park for Rope Drop. Those first two hours or so are gold in Disney. You can get SO MUCH DONE with minimal to no waits in line.
And maybe I'm a bit confused, but can't EVERYONE use FP+??? As I understand it, once you get into the parks, it's open to anyone with a park ticket. No, you may not be able to pre-book, but once you get into the park, head to one of the further FP+ kiosks, and make book some FP's.
I can't see going all the way to WDW, spending all that money, and being satisified with only the rides that no one else wants to go on.
In the 3 trips we've taken since 2008 (all over the summer) we've only waited ONCE for more than 20 minutes. (I mistakenly thought we could get a FP to Toy Story Mania when we arrived at DHS at noon. That made me a Rope Drop convert, and we've never looked back.) And we've hit every single headliner, multiple times, on each trip.