Seems about right.

The purpose of sanding after a few coats is to remove the inevitable bits of dust, grit and lumps of hard Tru-Oil that always seem to end up in the finish. That's all you really want to do, otherwise you're sanding away the depth of TruOil that you're trying to build up. You are of course building it up enough to sand it back flat for a glossy finish, as 3-4 coats will seal the surface well enough to protect it, though these may wear through quite quickly in places if you give the guitar a lot of use. What you don't want to do with intermediate sanding is apply six coats, then sand five of them off again. So just lightly sand with very little pressure applied, just enough to remove any obvious imperfections in the surface.

Two weeks is the minimum curing time, but if you can wait four, then the finish will be a lot harder with a lot less risk of sanding through when sanding flat before polishing. You want to sand back until you've removed all 'orange peel' dimples, with no bright spots of unsanded finish appearing when you hold it up to a light at a shallow angle. Then you can wet sand going through the fine grits until P2000 or P2500, after which you can either switch to Micromesh for even finer grit sanding, or you can go straight to polishing. I prefer to go to a fairly high Micromesh grit as it does save on the polishing effort.