Hi,

As far as I remember, it's 1.5h from Phuket ferry pier, then you have a 40THB fee for entering the island.
From KBV don't know, I've never done it.

In terms of lodging, depends on your preference. If you want to get a good night's sleep, go to the secluded hotels on the east coast, if you want to party any hotel in the main area will do