A cheap set of dental picks for cleaning dirt out of screw heads, etc. A small needle-nosed vise grip comes in handy sometimes, unless you already have 3 hands...+1 on the zip ties and servo tape. I like my Dynamite hex drivers. I have a set of Losi's, too. No complaints about either set.
Get a screw set for sure, and some extra wheel nuts. Probably some spare spur gears and an extra pinion or 2. Not familiar with the 22 SCT so I really don't know what breaks on them.
Your tool set will grow as you figure your vehicle out and what likes to break. I'm going to guess that's a pretty popular truck at alot of tracks, so hopefully someone else at the track or the track's hobby shop (if there is one) can help you in a real bind until you can get your own tool kit/pit bag dialed in.