First, to answer the original question. I see my dd, sil, and gc once a week plus major holidays, but as the children get older and more involved with their peers, etc., I expect it will be less than that. If dd and sil wanted to cut back visits due to other activities, etc., I would adjust, surely. If I thought it were because of something in my behavior, I would apologize, if I felt able to, and try not to repeat what they found offensive.
As for teaching tolerance, I think it depends. It's one thing to show children, we accept gm even if she talks a little too much or we make sure there are some dishes at the table that vegetarian gf can eat. It's quite another to show them that we accept rude or bossy behavior or that it's ok for gm or gf to constantly criticize and belittle mom or dad. Sometimes, imo, we need to show children that we cut negative energy out of our lives or, at least, lessen it. And sometimes, unfortunately, that might mean going vlc or - only in the worst case scenario, I hope - nc.
Baby Reindeer - anyone watched it?