This is really cool. I have a few gripes / things I'd do differently after obtaining one.
1) it's gotta have stereo out for that Ric-O-Sound
2) neck pickup should be as close to the fingerboard as possible
3) I'd much prefer 5-strings and a wider neck, however that could be done.
4) I'd have a new pickguard made with a nice wood + finger rest
5) If those are "guitar" pickups, I'd throw EMG Super77's (active) or G&L MFD Jazz or humbuckers in it. Make sure I get proper lows out of the thing and possbily switch the pots to vol/bal & stacked tone of some sort.
I prefer short scales that are not much smaller than 34-35" scale length basses.
I'd try out DR Strings: Dragon Skins+ and BEAD(G) tuning one octave up like a piccolo. This works great on a G&L Fallout with that MFD humbucker and OMG Mode so, I'd be curious how it compares with some EQing.