Hmm...those are interesting points, Maya. I can't think of anything that I love to wear that wouldn't be appropriate to wear at all once I reach a certain age. I think maybe what Angie means is to find the item you love, but in a style that is more suited to your age. An example I can think of is polo shirts. A little pique cotton polo with an alligator/horse/lion/etc on the chest is a very young look, and probably shouldn't be worn after high school/early college. But Nicole (I think) and Tanya both have knit shirts that have a polo-esque feel to them, and both of them look great in those and they are appropriate to their age. I think this is what Angie is talking about. I love loose, blousy babydoll tops, but there are a lot out there that really juvenilize me, and just aren't appropriate for my age and lifestyle. I got rid of a TON of them in the "big edit" I had a few months ago. I didn't completely stop wearing them (I would be so sad), I just have to be much more selective in choosing them (hence my coral J. Crew blouse). Also, I think we (as a society) tend to think of all the things we can't wear/do once we get past "a certain age," but it goes both ways. Think of all the things that look kind of ridiculous on high school/college age girls--power heels, beautifully tailored suits, luxury fabrics, pencil skirts, couture detailing, etc....if I see a younger girl wearing those sorts of things, I think she probably has an interview (and looks really uncomfortable). Whereas I see a more mature woman wearing those and I think, "Dang, she looks good." Know what I mean?
As far as the DVF dress and cap sleeves, I definitely agree with Maya, you definitely have the arms to pull it off, San. Very toned and they look nice. I'm 27 and you have way nicer arms than I do (I avoid cap sleeves). As a rectangle body type, you could also try a knee length sheath dress. I've heard Angie say those are especially nice on rectangles.
Oh, and as someone who lives in Texas, which is the cut-off-denim-miniskirt capital of the world, I think there are very few mini skirts out there that look good on anybody, regardless of age or body type.