#1, yes YOU need to change it if you change from nimh's to lipo's
#2 YOU need to test the profiles for your self and see what works best for YOU. Different people like different things. Some may run the punch at 2 and others at 4 on the same track. So YOU need to do some testing and see what YOU like. Run the car for a couple min's pull off change the profile and try again and see how it feels for YOU.
