Do they have a place to set up a tent by the water?

Yes they do . get a map from them at the gate and you can pick one thats available.

The sites are about 50 feet from the water - at least ours was & most that I'd seen

Yes, several.

And they have some non eletctric spots by the water too, electric is 22$ a night, non electric is 12$ a night.

Yes they have a tent section by the water. It's really nice..

But do they have electricity if you're camping in a tent by the water?

Yes

About 350...