回复：请教pjiang, 863211等老师

1。如果我放弃学业在家（不使用EAD卡），what will be my status? Is there anything I should do to adjust my status in order to remain a legal status?

-Not need.

Or I need to do nothing because of my pending I-485?

-Correct.

2. I'm thinking to visit my family in China this summer, and I'm planning to apply AP. However, I'm still concerned I will have trouble with the Custom when I come back because I don't have any type of valid visa (F1/H1/H4). 

-AP is fine enough for you to come back to US.