There are a few songs I play where Drop D tuning is required to get some nice, bass-heavy, open 6th string notes. It also facilitates many of the chords in the song in addition to adding a full tone. The rest of my playing mainly stays in the Standard tuning realm.
Is tuning down to Drop D for a few songs, and then back up to Standard, bad for my guitar?
I do this at most ~2 times a week, usually when I play through my entire "setlist" of the songs that I can self-accompany to, to practice. It will stay in Drop D for ~10 minutes, maybe less.
I will occasionally check the tuning of other strings when going back (by checking the 6th string E against a tuner and using that as a reference), and a few other times a week if I find the tone sounds off or if I haven't done it in a while.
At the moment I play on a solid-top Fender (DG14S), beginner guitar. At some point I will be upgrading, and I don't want to ruin a new guitar by repeatedly changing the tuning.
As an aside (I know I shouldn't ask two questions in one), does the same hold true for an Electric guitar?