Meaningful Conversation restores two turns worth of time on the clock, and doesn't cost any energy to use, with the drawback that it has zero effect if the customers are too horny (as in, if there's a little heart icon on the status screen). It lets you get significantly more out of each shift working the bar if you're not working topless, so long as you wait at least two turns before you use it and don't Flirt until after it's been done, but it ceases to have any value if you've already got your tits out. In the completed game this could be just for early in your progression, before Cat is trained enough that she always works topless instead of giving you the choice, or it could be the start of an alternate less-slutty progression path.
I think tapping on the wall requires a higher degree of training than masturbating in front of the hole does, as well as having masturbated there at least once. If you start visiting the hole in the wall regularly as soon as you can, you'll see that option greyed out for a long time, but if you only go there after you've pretty much maxxed out corruption (as far as the current build goes anyway) it might unlock on your second visit.