I can't imagine running an STL mesh as machine code. It would be very hard on the machine, and would probably look like hell. I've never done it of course, so I could be quite out to lunch.
BTW, since we are talking about expensive software here, and future purchases (after the student priviledge has expired), then I wouldn't go blowing a wad on Solidworks, and trying to skimp on the CAM software. That is why I say OneCNC is a good balance (pricewise) for both modelling and CAM together. This is only one choice of many possibilities out there, so I don't mean to be tramping on anyone's favourite software combo.