Why anesthesia, especially so late after already attempting placement in another specialty?
To answer your questions....
1) You don't have a choice, your PD must be involved and a LOR from him or her (or at the VERY least an assistant PD) will absolutely be expected. You matched into a prelim year with no advanced spot - they will expect you to be applying again this year, it's just a fact.
2) You can (and should!) apply to R spots, but there aren't very many of them. These are the spots targeted by others switching specialties or those in the military - often with solid scores. Plus your stats are borderline and a lower Step 2 hurts. You'd be better applying for C and A slots as well to broaden your application. You could offer a research year if you match A, but honestly you may have to be willing to repeat intern year in a C program.
3) Its an uphill battle, for sure but not impossible. You'll need Anesthesiology exposure and a LOR (preferably more). You should be ACTIVELY lining up a rotation prior to graduation if that's what you want to do - it's been a few weeks now since march. Also see if you can do a rotation as early as possible during your intern year. Seek out DO friendly programs, and if you are really serious consider an AOA program.
Goood luck!