1) You're right: revealing is the wrong word. Better to say: provocative, exciting, attractive, seductive, tempting, alluring, inspiring.
2) The clothing Sophia feels comfortable in (at school and outside) is what you usually see her wearing when she's not bound by Aiden's tasks. When she has been forced to dress in a sexier way so far, her attitude has always been portrayed as that of a woman in severe discomfort.
I can agree with you, with the fact that on a hypothetical scale of discomfort Sophia might feel better walking around her school in a business style dress (less revealing but more provocative) than in a sundress (more revealing but less provocative), but what we're discussing is the assumption that Sophia (once dressed like this to acquiesce to Aiden's task) would go around the city (maybe in another school?) in such an outfit. Why would she go around the city dressed like this, if the only reason she goes around her school dressed like this is because she is being blackmailed by Aiden? Should Aiden's assignment involve Sophia going to another school?