Re: Kent narrows vs. around Kent Island
Yes - St Michaels marinas are expensive. If you're willing to pay, you might consider mooring at the Maritime Museum. Worth a visit!
There is lots of room to anchor at St Michaels. Some of it inside, lots of it outside. The water taxi runs both inside and outside.
There's also a couple other places close by: Leeds and Hunting Creek. Nice, calm, secluded.
Regarding Kent Narrows - haven't been through there for a couple years. Used to be well marked. Lots of boats go thru there, did it several times, but never really felt comfortable.