RE: another typical noob question
There have been a few magazine articles over recent years in which they asked pro racers about their radio settings, and in each and every one the "pro" said they'd left all whistles and bells and various settings alone and used it as it came set out of the box.
All you "really" need is steering and throttle "trims," like you said you'd used, and once you set those you really never have need to touch them - and "steering exponential" which allows you to limit the amount of throwof the steering, so you can dial in or dial out the steering relative to where you're racing and how tight or not the turns are.
Do you need all the extra settings some radios offer?
Idoubt it.
Can you get by using some of the cheapo radios that come with most RTRs?
Possibly. But the main problem IMHO with traxxas, losi, associated radios is their quality. They work fine, but just feel cheap.
There are some other quality radio (in AMand FM) out there still - and now that seemingly everyone's gone to using the $400 high-end 2.4ghz units they can be had quite cheaply.
The problem I see with so many so-called racers is that they buy radios thinking it will make the a better driver, or thinkingthat it makes them a racer, and yet they're still as bad as they used to be before spending big bucks on a radio. Don't get caught in the game where you have a fancier radio than you do car.