Regarding transit times for water taxis - you will need to clear OUT of BVI (West End) and then into USVI in Cruz Bay. Depending on the volume of water taxis or private yachts clearing in and out in both places this could take some time - especially on a Saturday morning. You will physically take your bags and clear in in Cruz Bay (at least that is what was required in April). The taxi from Redhook to STT can take up to 45 minutes depending on traffic.

You have to have checked bags to use the porter at STT - or be willing to pay $20 per person IF they are willing to assist. Global Entry requires your physical cards (we use it every time).

I agree about skipping Scrub. I would also do this CCW and have your friends meet you at JVD.