as far as the air filter, Dynamite makes a good one,
https://www.amazon.com/Dynamite-Complete-Air-Filter-System/dp/B0006O4ZPQ
your drill is not spinning fast enough to start it, the rotostart in your link may work with the hex drive you are using now, but the shaft that comes with the rotostart...
i would disassemble the carb and clean it up. good chance old fuel gummed up and is plugging up the needles.
Thunder Tiger and AE both designed the MGT/MTA-4, they are the same truck, just AE sold to the NA market, and TT sold everywhere else.
i really hope they do bring back he MGT and Mini MGT, but i dont know, AE is typically a more race brand.
they are great trucks though. have 2 of the MGTs, and 2 of the Mini MGTs. i will 100% say are better than the T-maxx.