1. he must put down his spouse's information in the forms.
2. yes, because your basis is still his 140 petition. You use his PD. You can submit I-485 if his PD is current, that is, by Aug 17. Otherwise, you will need wait till the next time his PD is current again.
3. If you have a valid F1 and not using AP or EAD, you can continue.