So I followed Waz advise and sanded with 120 grit overall, I don't see any machine marks and really want to go smoother with 240-220 grit but will wait for a chance to test a stain on a sample of Ash. The stain I'm considering is waterbased. I've read that will raise the grain. Is this an issue I need to consider before going forward with waterbase stain? I plan on a MusicMan Bridge pickup and I know I have to route that out and need a template or at least purchase the pup first. Do I need to route before staining?
Lastly, as I wait, can I work the frets and fretboard before gluing in the set neck? Should I sand the board before dressing the frets?

Thanks.