Much to my surprise, I voted for the last option, because it's much closer than the next.
A year ago, my husband and I moved into a 55+ mostly-winter-home RV-oriented community, not for the social aspect, but because of the location and amenities. We already had quite a few established friends outside of the community due to our heavy involvement in the local wildlife parks. Many folks joining the community seem to be focused on the social aspect.
Much to our surprise, not being really social types, we have ended up making several good friends within the community. I consider anyone within our "wall" a neighbor as we see each other all the time walking and cycling, at the clubhouse, etc.
We already had a lot in common with one immediate neighbor when we moved in, and since we have become very close, in spite of them being my parents age. We keep an eye out for each other, bring each other gifts when traveling, email, and have many impromptu conversations across our back yards. Several older couples down the street we have become close to as well.
We participate very little in the community's planned social events, but we do socialize quite a bit with couples we have come to like very well. We're part of a smaller 50s "younger" crowd within the community and have found we have an amazing amount in common with these other, younger retirees. Enjoyment of outdoors/nature, love of travel, and love of good food and wine, seem to be the basis for the friendships developing.
I have been surprised, because we already thought we had plenty of friends in the area. And only a tiny percentage of folks in our neighborhood are really plugged into the local wildlife scene. But, it turns out that there are some really cool people around! It's worth noting that we found most of these interesting folks by giving nature-oriented tours for our community - not by going to a community-wide potluck or party.
Audrey