most women in my class wore dresses, though many of them didn't have an appropriate understanding of what was appropriate.
strapless? not acceptable. this is a professional event, not a social one.
cut down to your xiphoid? not appropriate, i don't care how much skin we were showing in OMM lab those first three weeks..
side-boob? (i kid you not!) what the hell was she thinking?!?
i'd base a tights decision on the weather, and otherwise make sure my thighs and cleavage weren't showing (my dress was sleeveless, but since the jacket was on, it didn't matter). common sense, really, so it sounds like what you've got in mind is perfect.