I have a Squier Starfire (basically a rebranded Dearmond) that I bought used back in 2005. The only thing I've upgraded is the pickups...I swapped out the Duncan Designed HB101N and HB102B for Epiphone Probucker PB2 and PB3.

So my question is this...what else can I upgrade? I would like to get a Graph Tech or similar nut, but I have no idea what kind to get. It's such a rare guitar that almost no info is available online and no one makes anything specific for this guitar. It already has a genuine Tune-O-Matic bridge, and the F-holes are too small to do any sort of pot upgrade- and no, there's not an access panel on the back or under the bridge pickup like on some 335's. The tuners are ok, but they're stock and aren't any sort of brand...just no-name sealed chrome tuners. I also have no clue how to upgrade the tuners, or which ones to get.

Any ideas?
you could upgrade the nut. new tuners are nice, unscrew, unbolt, replace, easy.  pots aren't as difficult as you may think, tie a string around the shaft, fish the pot out, do the wiring, replace string on new pot, pull it through.