Re Gummed Up advance: Yeah, when I did mine (Which was kinda gummy as well) I just gave it some good shots of brake cleaner, and brushed it out a little before a few shots of PB Blaster. There IS a way to twist it/turn it that lets you check the "Advance action" and make sure the mechanism at least moves freely. I can't remember what the trick was, but I'm sure you've found it, or can figure it out easily enough.
As for vacuum leaks at the base of the carb, sounds like you found your culprit. Your idle will bump up if you start running lean, so it sounds like you've definitely got a leak there. As for my personal experience, my similar leak was a bit of a pain in the ass... Unfortunately it wasn't the seam between the carb and the manifold that was leaking, it was actually the seam that separates the top part of the carb from the bottom part. Sadly you need to remove the whole carb in order to get "Underneath it" to tighten the screws that hold the 2 halves (Top and bottom) together. With a little monkeying around you should be able to see if the whole carb is loose or whether it's just a leak between the 2 halves.
I'll keep my fingers crossed for you that it's between the carb and manifold. If it IS between the 2 halves the task of taking off the whole carb may seem a little daunting, but it's not TOO difficult if you take your time and really pay attention to how everything hooks together before diving in. PLUS, assuming you're not in Cali, things should be much easier:
As for helping? You're more than welcome to any advice I can provide... I'm glad to help in any way I can to help keep more old school Hondas on the road, plus I get to pay it forward. The great people on this site have been an awesome source of help to me (Shout out to Dr. Snooz!), and I'm just glad I can contribute to "the cause".