I prefer O'donnell plugs. #89, #99, or the "Sport" plugs (Red, Blue, Purple). Never had a TRX 3.3, but the 2.5 i had didnt seem to ever like keeping TRX or OS plugs alive.
33% nitro is fine. I run 30% in all my stuff. Dont HAVE to use Traxxas' fuel... just make sure whatever fuel you run has a quality oil in it.
Jato's have definetely proven to be a platform capable of alot.. like going 93mph. I would have built one myself... but they are way to common these days.
Current IMPBA Twin Gas Rigger World Record Holder.
One of few to ever go over 75mph through IMPBA timing traps with a Gas Cat
HPI Firestorm 10T // Hyper .21 Bigblock Power
HPI RS4 EVO+ // Hyper .21 Bigblock Power