I like that (they run on smoke) that's too funny. the front tries to climb the rear kinda sounds like the axles are too close together. if you post some pic's that would help.
as for the grease i use marine grease it's thick, sticky and dielectric.
the screaming motor could be the drive gears or the motor just needs cleaned. if you take it apart you can run JUST THE MOTORS in a cup of water to help clean them out.