Dave, on your nose high issue... You could add Lippert's bolt on Correct Track 2 axle alignment system. Yes it's designed to align axles but it also raises your RV 2". I had the same situation on my last RV. Pinbox all the way up and the hitch all the way down. The CT2 system is the only thing to get me level. The best part is it's a Lippert product and won't void your frame warranty...
As to the pinboxes, I run the Reese 5th Airborne. While it doesn't completely eliminate chucking, it helps greatly. I chose it because it's the exact same shape as a Lippert solid steel OEM box and therefor can fit under my factory fiberglass pinbox cover. This makes for a very neat install. On my last rig, I had the now discontinued Trail Air Tri-Glide. Retailers still have them and this is the best system out there for completely removing chucking. The Rota-Flex that replaced it has had some issues and I'm not sure if it's ready for prime time from the reviews I've read. Maybe someone with experience can chime in. The other options you mentioned all have strong followings so I'm sure they are good products as well....
The video in this link shows the complaints of excessive movement I've read about the Flex-Air:
http://s293.photobucket.com/user/crz...5rwfv.mp4.html