Ive never been happier than when I ditched the lift assist wheels on the planter so I cant really help with that. We tried it but the lift assist we had were made for older tractors that didnt lift as high and when I tried it, the planter was tipped back way to far with the 3 pt up so I put the top pin in and just carry the planter. 

Plumbing it into the 3pt is the only way to go if youre using them

If youre dead flat you can get away with pinning the wings, but if you have any hills at all, let them float, I prefer to have the gauge wheels out front on the wings