BTW I kinda love your quantum planning approach. It's honest and accurate! If you're 50/50 on going to something, be transparent and tell others that. If they don't like it, that's on them, not you.
"Hey, would you like to come to a dinner party at my house on Saturday. There's a 50/50 chance that I'll turn you away at the door."
Don't make your indecisiveness other people's burden.
"I've got a pretty busy day that day and am not sure I can make it" - transparent
"I don't know if I'll be up to going to that that day" - transparent.
"Hey, maybe; if I find nothing better to do" - transparent.
"50/50 chance I'll be there" - all the charm of the last of those, without the transparency.