well, the vice chief and the geisha are based on true people, so it's possible to look up what happened to them...

i think they got married after the revolution, but there's also the possibility i'm confusing them with Katsura (from the ishin-shishi), who had a geisha and promise to marry her after the revolution... of course, there's a chance that both couples got married, if you really need to know, just run a search on the shinsengumi in google, it's somewhere out there....

since i've yet to watch the entire anime or to read the manga (i'm waiting for AF-F release, yay for the machosizt part of me!), i can't answer your questions...

however, I have to add that for me, Shinsengumi forever will be Saitou and his Gatutse, can't beat that...

"shinsengumi was shinsengumi
okami wa okami
soshita, hitokiri was hitokiri
doro, Battusai?"

"you bribe a man with money
you raise a dog with food
buy you can't tame a wolf of Mibu!"

man, Saitou didn't get enough screen time in PMK, they wasted it all on the gay ninja and his completly uselss sister...