Hi - new to this board - I usually am in "Weddings and Honeymoons" threads, but I used to live in Orlando and went to PI often. The last two times DH and I were at PI we were able to get a ticket to just one club - but if I recall correctly the Comedy Club was not part of that policy. We got tickets to Mannequins because I like to dance - he likes to drink beer and stand next to me while I dance
If you go, Mannequins is 21 and up so there aren't teens there and the rotating dancefloor and steam and confetti drops are fun.
If you like 1970's and 80's music 8-Trax is the best, the dance floor is small and crowded but it's always a fun group and you can stand above the dancefloor and enjoy the music. Motion is good if you like hip-hop (we don't). The Beach Club has live bands (usually cover bands but I've seen some fairly well-known Florida bands there too) and a great bartender.
Anyway, I think PI has changed it's format to more closely match Universal Studios City Walk where anyone of any age can walk around and you pay an individual price to get into most of the clubs.
If you are a passholder or have the Disney Dining Card you get a discount for full admission to PI.
I had my bachelorette party at Jellyrolls - FANTASTIC!! We had a lot of fun

and the small cover charge is totally worth it. We took a cab to Boardwalk from our resort (CB) it was just easier than trying to get a bus and we didn't want to drive.
Have a great trip!