I stop an entire session when I dont think Im playing well which is something you just have to be honest with yourself about. There arent really a series of questions that determine how well Im playing, I just think about how Ive played the last few hands and if I clearly kept fucking them up, then Im done.

In terms of leaving a table I will stay until the mega fish leave. At $100nl and below for 6max/5max there are typically atleast 2 megafish at your table, when they bust or leave Im out of there and trying to find another good table. Even if it gets down to 3handed, I will stay as long as that fish is there.

At the small stakes I really dont think there should ever be a time where you are the fish at the table. Even if you arent a great player there are simply so many tables available for these stakes that you should always be able to find a table filled with players worse than you. Even if a couple fish leave, you still arent going to be the worst player there if you are posting here.