They would have to demorph and remorph every two hours. Which means between classes, probably in the bathroom. I don't know how long classes are in California, but if they are two hours long then it wouldn't be possible.
Now I could see Rachel giving Tobais school lessons after he got his morphing powers, but I don't know if she ever did that. I don't see much reason for Ax to attend school.
Yeah, it'd be cutting it really close with the timing, at my high school I think my classes were...50-55 minutes, so it'd be really a stretch to my mind. That's one major downfall.
I dunno if it was just in however many fanfics I've read or if I remember this from the books -- but didn't Tobias help Rachel with her homework some nights? So he'd be there, with her, reading the book, he would've learned, it just wouldn't be official?
About the signing of report cards...yeah, I had a few friends who's parents NEVER saw their report cards, haha...
It could have made for great comedy if Ax joined Jake, Rachel, Cassie and Marco in class.
I wonder why Tobias enver went back to school after getting his powers back. Fear of school bullies?
It would've been hillarious, if they could find some way of doing it without drawing suspicion -- for example, Ax playing with his words too much - well, we KNOW several of their teachers were controllers, they would've noticed that, coupled with the hurried rush to the bathroom after class. I think it was just too risky. I don't think Tobias was too afriad of the bullies, I think he was afraid of either the time limit or his uncle finding out he was back - his teachers might start asking too many questions.