You can get the good wheels from Jett, SuperTRc, or Darrol Cady... They are about $12 for wheels and axels, you won't have any issues after that..

As far as your Viper climbing after the engine is shut down, that is most likely due to the fire wall having a negative incidence.. That could also explain the up trim you are carrying..

I use 10-24 nylon bolts to hold on Q40 wings.. No problems there and those hit upwards of 20G's on a full pull around #1..