Everything listed has been an issue for me at one point or another, but I think what bugs me the most, I mean the MOST is people wearing earbuds that CAN NOT HEAR anything else going on around them. I don't have a issue with earbuds but if you use them and can't hear anything else, that bugs me!
I say on your left but can't hear because of the music. Two wide runners both with earbuds neither aware of anything and not being polite about giving space. I have on one occasion to a really annoying person not paying attention at all rode beside the person, pulled out the earbud and yelled, I mean yelled ON YOUR LEFT.
I understand they have as much right to the trail as anyone else but be polite.... I avoid the MUP on weekends, just too busy to be fun for me.