1. No, you can't do this. You need to say no for now. If your employer gets and approved LMIA, you can then change the answer to yes.
2. Yes, a PGWP is an LMIA exempt work permit. However if you want to claim the 50 job offer points under Express Entry, then your employer still needs to get the approved LMIA. If you don't have an approved LMIA, then you can't claim the 50 points.