What I heard from the SSGT at my OSO office is that it's up to the individual OSOs to set deadlines for application packages to be complete, so it may vary from office to office. Mine still hasn't been set in, but I think that I might be an exception to whatever my OSO's rule is since the delay in my case is due to factors beyond my control (medical waiver, everything else was done early May).
As far as ground vs. air... does anyone know whether it's possible to drop an air contract (switch from SNA to "Basic Officer" MOS designator at TBS)? I've heard of people doing this with a little bit of extra paperwork, although I've also heard rumors that they stopped letting people do that recently due to the decreased need for ground officers. I'd love to fly, although my girlfriend isn't too thrilled about the whole 8-10 year air contract, and being a Marine officer is more important to me than getting a particular MOS. I wouldn't sign an air contract if I had no intention to fly, of course, but I would still like to know whether that's an option.