(Note: I'm not trying to be nasty. If staff deems that this post is unpleasant, or would upset somebody, I'll understand if it's closed.)

Is there, or should there be, a guideline about how many posts in a row to make in a single thread?

Some members apparently don't know how to use the multi-quote feature, so instead they quote several posts in a row individually and add a very short "me too" kind of answer. They may end up with a dozen or so successive "me too" posts on any given thread. It's more annoying than anything else, but I've seen forums where they limit individuals to three posts in a row in the same thread. After that they can't post in the same thread again until somebody else does.