Hi,
sounds you are not very experienced with electronics? Well, here are some answers:
1) third number is exponent. 151p means 15 x 10^1 ==> 150pF (153pF would mean 15 x 10^3 ==> 15000pF)
2) L3 is the inductor for the LC resonance circuit. Important for the RF frequency and radiated power. I assume they describe 7turns of 0.3mm copper wire with 5mm radius.
3) As the application describes an RC car, these are the motors for driving and steering
4) yes, 3.9MegOhm