Is there usually a lot of people there this time of year on weekends?

Hocking Hills is always crowded any time of year. Good time to go is during the week.

Yes

We were there 2 weeks ago during the week and it wasn't super busy.

Yes. We were just there this past weekend.

Yes they are very busy throughout the Summer

I would guess yes but this was the first time we went in spring. We just went two weeks ago and there was no parking left by the time we were heading out at about 1pm. The trails were pretty clustered on some points.

Yes this is a busy time of year especially on weekends

I was there last weekend and there was a lot of people at old man's cave

Not really no but they do pick up a bit in July and even then it's still very peaceful.

No, unless you go Memorial weekend, that's one of the busiest camping weekends.

No