We have done a variety of drop off/pick up in the USVI. Here is my 2 cents.
If we are planning on sailing St. John and the east side of St. Thomas we will usually have crew meet us or drop crew off in Cruz Bay using the St. John/St. Thomas ferry. There is a ferry that goes from Cruz Bay, St. John to Crown Bay, St. Thomas. This one will drop you off much closer to the airport. It is a little more expensive but it saves on the taxi cost from Red Hook where the other ferry drops off. Here is the link to the Crown Bay ferry:
https://www.interislandboatservices.com/ferry-trips/crown-bay-to-cruz-bay/. You can now pay for the NPS mooring balls online rather than having to go over to the pay station. I have attached the QR code you can use to pay once you have tied up to a ball. The NPS mooring balls for St. John are still managed through Recreation.gov. The new balls that I mention below are managed through VIPCA and Boaty Ball.
If you want to check out some of the bays in St. Thomas you can drop your crew at Lindbergh Bay. They now have VIPCA mooring balls (paid for via Boaty Ball) there which makes it even more convenient. It is $10 for day use and $35 for overnight. We typically spend the night at Druif Bay (also known as Honeymoon Beach), Water Island and then take our departing guests over to Lindbergh the next morning. It is a pretty spectacular send off...you literally drop them off on the beach by dinghy and they walk up to the airport. If you are thinking about spending the night at Druif, contact me directly about a mooring ball. It can be a little tricky to anchor in there with all the permanent boats and the rocky bottom. Druif has a fun restaurant/bar right on the beach called Dinghys.
If your friends don't want to have a beach drop off you can get a slip for the night at Yacht Haven Grande. This is a very nice marina with a pool and docking is much easier than at Crown Bay.
If your friends don't want to take the ferry from St. John and you don't want to go to the east side of St. Thomas you could always grab a ball in Muller Bay which is the bay outside of Red Hook. VIPCA has also just installed balls in this bay and you pay for them using Boaty Ball. It can be choppy in there but they can easily find a taxi from Red Hook to the airport for about $20 a person. There are also now VIPCA balls at Lindquist (which has a lovely beach) and Sapphire. Sapphire would be easier to find a cab and has a couple bars and restaurants.