I’ve only been a member at Harborage Yacht club a few weeks, so I am probably not the best person to answer on the “culture” there. I will say that everyone I have interacted with there, both staff and members, have been very friendly. I think all the liveaboards are on the north marina, and it sounds like you were offered a south marina slip. I am also on the south dock, which I consider preferable since these are floating and not fixed docks. No need to concern yourself with the tides. The real community, in my opinion, is just over the Dixie Highway bridge to downtown Stuart, about 1 mile total. This is a great area with excellent restaurants, riverwalk, parks, shops and such. A really lovely town.
The walk from the farthest slip in south marina to the clubhouse is maybe 1/2 mile. The golf cart shuttles are always an option if you’d rather not walk. I’ve never used the shuttles as I like the walks but the marina crew are always all over with them taking people or caring for the facility.
There is some road noise from the U.S. 1 bridge nearby. It doesn’t bother me at all, and I can’t really notice it when I’m inside my boat.
Since nothing is perfect, I would say Harborage Yacht Club’s biggest issue is parking. There is no “lot”, just a long row of spots along the entirety of north/west side of Flagler ave. The marina shares this row with Tidehouse restaurant and the condo community. Each organization has its own share and they are marked with signs. I’ve not seen it, but I’ve heard the booting is aggressive if you park without a parking pass or in the wrong area. There is a small amount of public spaces south of the south Marina.