Absolutely can (note the snapshot happened this morning, so no for this fund). It's a pain to manage multiple though. The easiest way is to move all money to one wallet just before snapshot and move back after.

I've been using it for a week or so and I like it so far. Has a great feature set, the best I've seen yet in the light wallets.

You don't "have to", you have choices in wallet apps but there are tradeoffs. Daedalus is a "Full Node" wallet app; it downloads the entire Cardano Blockchain directly and verifies it with your computer. This gives you the best accuracy and trust into your wallet balance numbers at any given time. At present, all other Cardano wallet apps are "light wallets"; these are essentially services that download and verify the Cardano Blockchain on your behalf and then let you scan their database for your transactions. Light wallets allow you access without the extra effort, but you have to trust the service provider.

I haven't heard the standard mentioned before in Cardano circles so my gut says no, but maybe I'm wrong. Could be a worthy catalyst proposal?