I'm a well read grad student who's bluntly honest about all things, although I try to be most honest about myself.
"'DAMN THEATRE KIDS ALWAYS PUTTING ON SHOWS!'"
Well, I mean, that's what they do. That's like saying, 'damn athletes always playing sports.' That's what they do.
Just because you suspect them of using your booth to practice - which is right now an unsubstantiated allegation - to blame them for doing what they're supposed to be doing? That's completely unreasonable.
And yes, this character yells. 100% of the time. Ugh. Even in comics, where everything is all caps, all the time, the characters aren't yelling at you. It would just be a PITA to read the text that small. I'd go fucking nuts if I thought someone was yelling all the time.