Having spent my time in the Army (and hating every moment of it) I was a company clerk and worked in an office.
As for your discharge, I never had any employer make a big deal about my military experience. None of them ever checked into it. However, if you try to use military benefits, I think you might have trouble depending on what the Medical discharge was for. If you abandon your 6 year commitment after only 2 years and get the medical discharge, I am sure it will say what the discharge was for.
In general I don't think too many people will really care, most employers just want good hard working employees. As for collegs, they seem to have programs to help with transsexuals, or I would get that idea from the TransGender series that is on Sundance channel right now (I just watched the 3rd show today).
As for work history, you can ask your schools to change your records to your new name and gender. I know some employers will change that also, I have no idea if all will. I doubt that 2 of my jobs would change this (they were Christian Missionary groups) I don't think they look at me favorably now.
Sarah