I have to say, I'm not sure I know why you would want to set strong bounds here, particularly when it comes to sex. I have never had occasion to think "I wish I hadn't done that sexual thing that seemed like a good idea in the heat of the moment".
Have you ever been in a position in which you were tempted to cheat on a significant other? (I think you've written about being in polyamorous relationships...)
In a New York shop, I once got pressure-sold something expensive I didn't really want; when I said it cost too much, I was asked what I might be prepared to pay, and we ended up haggling. Since then, I've had a rule:
and I have been very glad of it on many occasions. I can go for a short walk to decide, and if I don't want it, I simply don't return to the shop. This means I'm deciding in calm surroundings, based on what I want rather than on embarrassment.
Are there other maxims I could adopt that would serve me equally well?
(Personal note: I'm in the Bay Area for a week after minicamp, Sunday July 29th to Sunday August 5th. Let's hang out, go to things together, help make my visit cooler! Mail me: paul at ciphergoth.org. Thanks!)