You need to decide what you want to do with it.
Race it - need to be very selective - bearings, shocks, oil, servos, radio, etc. - that they comply with the regulations of the track.
Bashing - need to isolate which parts are most likely to wear - I replace loads of bushes every couple of years on my MT.
Shelf - how blingy do you want it?
And YES - it all requires MONEY - this is an expensive hobby and can be very expensive for those a little less fortunate than others.
Remote kill is a definite YES, but check on the circuits. Mike1970 is not a fan, but perhaps there's a ruling against kill switches and their possible effects on others?
I was tired of re-gluing my MT tyres, and everything starting to look an absolute mess; cleaningm, trimming, re-gluing, only to rip the tyres off again, so I located a full set of new MCD wheels and tyres in Germany, de-glued - that cost big time (oven, boiling water, Acetone, etc).
Then I did some Google research and found an industrial strength adhesive good for alloy and rubber - still solid now after hours of bashing.
ONE FREE THING you can do is research. Use SEARCH on this Forum, and also my favourite, the Google research, then the bottom line ....... Who pays the bills? YOU - so at the end of the day, it's your decision.
Al.