EX-1L Custom, First Pit Bull Kit guitar

[McCreed]

I was planning to
-wet sand it flat with oil again (Do i wipe off the excess and the "oil dust" or do I let it stay and work it in with the application of oil?) starting with European 240 paper and then going up or, since i already flatted it with that, directly with 600-1000?

If you're intention is "grain filling" DO NOT wipe off the Tru Oil. The whole idea of grain filling using the "slurry" method is to allow the particulates (dust) to combine with the finish oil and fill the grain.
You need to let the slurry coat dry, then very lightly dry sand to knock down the high spots, nibs, pool spots etc. Then repeat wet sanding with Tru Oil as needed until everything is filled and levelled. THEN apply desired number of straight TO until you build up to the depth/gloss you want.

Personally I've never thinned Tru Oil. IMO it doesn't need it, but that's only my opinion. YMMV.

Another thing I'll add is when I grain fill with Tru Oil/slurry or when levelling the slurry coat, I don't go coarser than 600.
Once the grain filling is done and I start applying my build coats, I de-nib with a fine synthetic sanding pad (aka synthetic steel wool) but only after every 3-6 coats as needed.

- After that letting it cure for ... about a week (??)

I leave any top/clear coat for at least 14 days now (Tru Oil, Lacquer, Polyurethane etc)
The hardest part of finishing is waiting...

- Applying Carnauba wax

Completely unnecessary IMO. The clear coat should have all the gloss you'd want if the final polish is done properly.
I never used any kind of wax on top of a guitar finish. I know some do, but not me.