We'd love to have you and hopefully Summerville will turn out to be the community you are looking for! To answer your questions...
To my knowledge there is not a parade in Summerville that weekend, but I could be wrong. Have you checked out events going on with
Piccolo Spoleto? It starts May 23rd. I know they are having a Memorial Day Concert in Marion Square. That is Charleston, but you could stay in Summerville and go in for the concert...Most Summervillians journey into Charleston for the "city events." Summerville does have it's own events that happen and the best place to stay up on them is at the
Summerville DREAM website. I didn't see anything for Memorial Day though.
I would say for your weekend, make sure you get to the town square, have some ice cream, go to lunch at Mustard Seed or one of the restaurants in the downtown area...Drive down Sumter Avenue to see some gorgeous old historic homes. West Carolina Avenue is also a great one. I'm not sure what church you wanted to find, but there a number of them right in the downtown/historic district of Summerville...
Episcopal, Catholic, Baptist, Methodist, Presbyterian, Lutheran, all within a five block radius of each other and the downtown area.
As far as Subdivisions...Summerville is mostly mapped out according to developments or subdivisions as they are often called here. Some are older, many are newer. I'm not sure what type of home you are looking for, if you want a 55+ community,and what type of price range...that would help us to tell you what subdivisions to drive through.
If you can share a few more details, I have suggestions!
Hope this helps,
Foster