Hi @Martin280, I don't think setting limits is going to really help--if this is even possible. If you're uncomfortable with the prospective guest, you can always get creative and wiggle out, right?
I can give you one (haha, let's not start counting!) where a glitch in the Airbnb system didn't let me rate one of my best-ever guests, and I didn't realize it until another little glitch in their flawless system got me checking... I was horrified! Truly, I felt awful. Called HQ and though the agent completely emphathized with my frustration, could do absolutely nothing about it. What HQ told me was to contact the guests (through the proper channels), explain to the guests what happened, and tell them (I was their first stay, so this doesn't look good) that any other host could contact me for a referral. Big hassle for everyone, but I did it and my guests were grateful.
I understand the value of ratings, so I'm not discounting this totally, but the system doesn't always work...and we know that some guests can be jerks...and if you've been on this forum long enough, you know that some hosts can be a bit off as well. Could have been that a host asked the guest to strip the bed, change the linens and re-make the bed...or do all the dishes before leaving. What is important to some, and what seems insulting is a big sliding scale--in both directions.
Take a deep breath and re-read your correspondences. If you still feel uncomfortable, bail.
Best,
Kim