I came from a larger school, cell phones were prohibited...but that rule wasn't really followed. The students had the respect to have theirs turned off or on silent, but pretty much all of us were armed with one.
Then again, it was a common site to see a police car or a police detention bus picking up or dropping off kids, plus we had a police officer stationed in our school as well as police trained security guards (and our school really wasn't that bad compared to some other schools near me).
But back to the cell phone thing, he have had numours situations when a cell phone came to the rescue since the lines in the class are only connected to the school except for a few classes that need an outside line for emergancies (autos, metal and wood working, advanced baking/cooking).
And the teacher reading the text thing...its a 50/50 issue there, like stated before, with the world we live in, that could've been a message for any type of violent act tword the class, teacher, or a student after class. But it could also just have been a simple little "i luv u" or "hang out 2nit?"
Now the homework thing....can't help you there man (*whispers...thats what studyhall is for), let him do his work, but offer to help him if he needs it (by help i mean show him a problem or two, see if he gets it, not do the whole damn thing for him and have him write his name on it)
You sound like a smart guy, don't get caught up in bad things like that, yeah we all do our share of dumbass things, we still will. But try to keep it to a minimum. Like my dad always told me "think before you act".