i think that until the anime starts airing, the 'what if you were in Gensokyo' idea is fine right here, it will keep this thread alive.
if i was going to go to the SDM, i would go with Marisa, not alone. they don't really seem to like it when she shows up to steal borrow Patchy's books, but at least they know her.
only problem is, nobody in Gensokyo really needs a reason/good reason to start a danmaku fight. learn to dodge.