I have EAD but never use it as I am in H1B visa now.

I just worried if I can't find a job, say in 1 month or even several months, can I register myself as a student to maintain the 'same field' criteria?
Or, can I ask my boss to reduce my time to half-time due to funding issue?(or some other professors in my field?) Which is better for my NIW I-485 final approval?

Thanks a million!!