filter- personally, I 'd just drink out of the lakes inflow stream unfiltered, or, for no weight at all, just take some of those chlorine dioxide katadyn pills .They are tasteless.
bear can ? - has nothing to do with what you do with your tent, unless you take it all with you.
need bear can ? - I forget what the current rule is on MR (I went in 2006) , but even if no bear can required you should take it for other critters. The half-size BearVault is nice. The other option of hanging food may stop marmots but not mice. Ask me how I know.