I desire basic spelling and grammar in any RP partner. I can't help it. I can understand and ignore some stuff, but if I have to sit there and try to figure out what you're saying, nope.
Length and detail aren't really a thing for me. In fact, long and too-detailed poses when unnecessary make a scene drag, in my experience. I want the action, not the minutiae.
In general, one-on-one, five minutes between my pose and the other person's is about right. If it takes more than ten, I start grumbling, unless I was forewarned they'd be slow, in which case, I am also usually doing something else and will occasionally also take a while.
Too much %t drives Manu cray-cray. I use it sometimes when I am trying to do something stylistic (same with colors) often when I'm storytelling, but otherwise, I prefer they not be there. I just don't like them. I prefer double carriage returns.
I always am playing 3-pose rule unless there's initiative involved. I don't even ask, which some people might think is rude, but I have been at this long enough to not care. And if I am playing with close friends who know me and play with me often and we have meshing styles, I'll skip all the fuck over the placed, I do not even care.
Key to playing with me is knowing that I put as much effort in a one-line pose that I do in a long paragraph, because often the brevity of the pose says something in itself. Also, I don't like to be kept waiting and I don't like to make people wait.
Also, key in any scene, is to know when the scene is over. It is perfectly all right to say "I think we can wrap this scene up ehre" and then go play with someone else if you want.