I mean since you're in just practice mode right now its all good but if you were to race because of all of these upgrades, I'd imagine they would put you in a mixed/open 2wd sct class, or SCT stock class. Most SCT classes on carpet are 2wd anyways and most likely stock/13.5 so if the track isn't that strict on rules they'll probably put you in there.
Power setup, 4600kv castle is, pretty good but indoor carpet it might be too much, you might wanna turn down the throttle if you feel like its too much, for the size of the track, or gear down. since most likely you would have more motor power than gearing power. I run 4000kv hobbywing on 23/86 and it is fast both on indoor carpet and clay, speed wise, on the straight aways, not lap time wise.
Tires, Traxxas tires you have now or what the owner said *can* work, if you wanna stick with traxxas tires, S1 compound is the way to go, but it's not that grippy as an actual carpet pin/wedge tire, actually could help you drive better since you don't have that much grip that you're traction rolling every turn you know. But in actual terms here, I run Schumacher Mini Pin SC (Blues) with DE Racing closed cell inserts. Been running that on carpet for short course for years and its a good all round tire for both office carpet, eos, crc, ect. If you find it too much traction what I do is the electrical tape method on some pins around the sidewall to remove that initial edgy-ness feel, or trim a couple rows of pins can also help. Those Schumacher tires I mentioned/use, I rarely see ran at my local track, most people run Fuzz Bite rears and Swagger fronts, or Proline Prism's. Usually all carpet generally would be the same tire recommendations, depending on the type of carpet, but mostly its driver preference and how super traction or more... (trying to find the right word here...) relaxed??? feel tire wise. More softer compound, more harsher the tire will be in wear and traction. More harder compound, more less harsh the tire will be in wear and traction. This is just speaking from my carpet experience. If this track stays offroad, I would assume they would allow regular pin tires but I know some tracks do mixed onroad/offroad carpet on the same track and they have a rule where you can only run slicks (and some sxt 3.0 compound) so I guess it depends from track to track.
General setup, adding on to what
@luke66 said. Doing a Mid Motor conversion will help ALOT in cornering and jumping and overall drive-ability since you would be moving the motor in front of the axles and more central weight distribution, compared to stock Rear Motor layout where it's behind the rear axles making it more rear heavy. I still have yet to done a MM conversion on mine but I drove Luke's car a couple months back and all I can say it makes a huge difference, but, it can cost alot of time in converting and setting it up for your track, although pretty cheap if you use Nitro Slash parts from Jenny's RC. (I still run Rear Motor setup, I don't race mine, more like track bash inbetween rounds of racing when I race my actual buggies lol)
Shocks, you would want some thicker shock fluid, firmer springs and a overall lower ride height for carpet use. Me, I don't have alot of time to test and tune so can't say for sure whats good but I run the big bore shocks you mentioned, with the included red springs. I tried 50wt f/r and that was too thick. I run now (if I remember) 35wt front and 30wt rear and some preload clips to make it stiffer, I think that's a good starting point. or 40wt f/r and go from there. Haven't tested out sway bars yet but they will for sure help alot.
Here's some running footage of my truck last time I ran it on carpet:
You see in harsh/hard turns in corners it likes to pop up the outer rear wheel, still haven't figured out a solution for that but I would make a educated guess that thicker shock oil and thicker sway bars would help.
