回複：PJ老師，繼續請教。

1) You can keep full time H-1 and attend school w/o F-1
2) You may change H-1 to part time so as to attend school
3) You may work as much as you like in EAD and go to school

You don't have to be in F-1 so as to attend school.
You must work FT so as to maintain H-1.
You don't have to be in H-1 for GC, but you'd better in FT position for GC if you're EB primary applicant.

You can't be in half H-1 and half in F-1. You can't be in F-1 at all, after submission of I-140/I-485

http://blog.wenxuecity.com/blogview.php?date=200804&postID=4128#attendSchool