here's a big pile of questions: need setup advice

[lincpimp]

Ok, keep in mind that the longer can motors make more torque. It seems like mosty use a 1515 for a mt or truggy. Your muggy will most likely be heavier than a std truggy, so the 1521 may be a good choice for you. I would say that around 45k rpm is good for the motor, so at 6s lipo=22.2v you will want a 2000kv motor. 2000kv x 22.2 = 45k rpm (or so)

You battery choice sounds good, I would think that you will get somewhere between 25-30min with that pack, considering vehicle weight and gearing. Having the truck geared for 60mph may cause some issues during regular driving. I would say to have gearing setup for about 45mph regular, and have a larger pinion you can put in for speed runs. The lower gearing will cause less heat, and offer better runtimes.