I haven't been back to the Pocomoke since the late 80s, but unless the pulp mill near Pocomoke City has shut down I'm sure you can easily navigate to Pocomoke City. This is a commercial
waterway with tug boats pulling barges to the mill from the Chesapeake. The entrance to the river is via a dredged and man-made channel, but once inside you should see 15' depths or more. There used to be a free town dock
in Pocomoke City just before the fixed bridge (35' IFRC). The river is wide and deep enough to anchor
near the shoreline, but you will need to insure you don't swing out into the channel as the tugs are on the river day and night. Also there is normally a fair amount of current
on the river. Not much by most standards, but a lot by Chesapeake standards, and can make anchoring
a little bit of a challenge.
Here is a link to a description of my first trip to the Pocomoke, back in 1979.
I don't know about sailing the River as it meanders quite a bit, but with the normal SW breeze of the summer time you might be able to keep the sail drawing most of the way. Pocomoke Sound is very broad and shallow and can get pretty choppy with a fresh breeze out of the SW. No problem going up the sound, but can slow you down going the other way. One option is to use the cut between the Annemessex River and the sound. This cut is used by watermen going to and from Crisfield. I went through there in my boat drawing nearly 5' and saw some depths near that level, but never touched.
The Pocomoke is a beautiful river and well worth the trip.
Again, I haven't been there since the 80s.