J-1 and I-130

Hi I appreciate your comments very much!

I want to quit my J-1 right now due to a bad boss, and file I-130 immediately, my question is as following:

how should I fill the J-1 expire date on the I-130 since I don't know yet when my employer will inform USCIS?

how long it will take for me to get the nonimmigration visa? if I don't get it before the J-1 expires, what would be the consequence?

EDA has to be filed together with I-485? or I can file it alone or together with I-130?

should I hire a lawyer? or it's simple enough to follow the instructions provided at USCIS website?

thanks a lot