That is the generic route I would take as well. The question is where in St Pete are you going into? The various passes into the St Pete area allow a number of options....but I would suggest that North Pass not be your primary. If you are going into Tampa Bay, and into the Pier area, you might want to alter your route from the seabouy. You will not need to stay in the ship channel, either side is fine...and watch for ship traffic. Stay clear of the south side too close to Anna Maria Island...tends to get shallow, as does the north side of the point.
DISCLOSURE: I am not looking at a chart at the moment....but I do know those waters quite well....
1980 Cal 39 Mark II
St Michaels, MD