I find it hard to equate the catsuit with turning T'Pol into an object. I mean, I understand your point, but T'Pol was clearly a senior bridge crew member and without a doubt commanded respect from the crew. I believe the overwhelming majority of ST viewers saw her as an integral and respected member of the ENT crew. This holds true even if we did notice her figure.
It's like I've said before - I feel like people make a mistake when they act like we have to neuter our perceptions of people in order to treat them as people and with respect. There are several women that I work with that my primitive animal brain has considered and told me that I would find it pleasurable to have sex with, but I'm a responsible adult who knows that that doesn't entitle me to anything, isn't work appropriate, and isn't any measure I should use to judge their value as a person or as a coworker, and so I don't.
The problem with T'Pol and Seven is that they work on two levels - in-show, and meta.
On the in-show level, all of the above mostly holds true - Malcolm can think T'Pol has a nice bum, or not, and it shouldn't affect his ability to work under her in the chain of command or influence how much he respects her in the slightest. Seven can wear what she wants, and presumably The Doctor had some medical reason for dressing her that way initially - whether that had to do with comfort where her Borg implants had been removed, or possibly psychologically: he made her look aesthetically pleasing because he knew she would have enough trouble coping with the psychological aftermath of her assimilation and adapting back to her humanity as it was, so he may as well give her every advantage he could. Or, maybe he just wanted her to be attractive as a matter of personal preference, without any ulterior motives, and given that he was going to have to perform physical reconstruction on her while removing the implants, and choose the initial outfit to dress her in afterward, anyway, I'm not sure I see a problem with that, so long as he didn't cross any ethical lines in doing so. Or, The Doctor
could be a bit of a perv, and we were supposed to realize that about his character - which is still realistic enough, if unfortunate, but I don't recall anyone ever mentioning or admitting to that.
On the META level, though, we know that in both cases, the actresses and their outfits were chosen specifically to boost viewership in that precious 18-34 male demographic through sexual enticement. And in that sense, the two women and their characters were objectified. To be honest, I have very little trouble with actors and actresses being selected at least partially on looks in most works - TV/movies are mostly supposed to be escapism, so let the people be beautiful. But that also means that there's no real point in making them sex objects - when the pool of people you're going to choose from is already pretty much guaranteed to be above average in attractiveness, why not focus the characters on other positive traits like courage, bravery, loyalty, etc, rather than "look at my boobs"?