> 1. Can I apply for NIW BEFORE I actually join the job in the
> underserved area? If so, how much in advance can that be done?
Look for posts by 'hashitoxicosis'. He filed a NIW if I remember correctly before he was done with fellowship. However, at that point he was a board certified internist and held a medical license, so he already fulfilled the job requirements for his NIW job. But that way, he had his NIW approval in hand, allowing his wife to file I485 and get an EAD seamlessly after the J2.
> 2. I have used up 5 years of my H1B time. Will 1 year of H1b visa be
> enough to join a job in an underserved area and file for NIW after J1 visa?
I thought you are on H1b, not on a J1 ??
You can file a NIW directly from H1, you don't need to be on J1 for that. The only difference between J1 and H1 is that in H1-->NIW the 5 years only counts from I140-NIW approval. In J1-->waiver-->NIW the 5 years count from start of the waiver job.
I140s take between 1-18 months, the numbers on the USCIS website are meaningless. Most seem to be in the 12-15month range. So, if you want to wait for the I140 to be approved before you file I485 (generally a smart idea), there won't be enough time. If you file I485 before I140 is approved (concurrent filing), you should be able to get the EAD in time. (the only problem is that at times with self-petitioned cases, the EAD is put 'on hold' until the I140 is approved. This could throw a wrench into the process. Although you are in lawful status due to a 'non-frivolous' I485, you couldn't work)