Except that part of being a Startfleet Captain is putting aside your personal feelings when they compromise you. Hell, Trek '09 covered that one.
Janeway had every right to feel as she did. That doesn't mean she's in any position to abuse her power as a Starfleet Captain in order to act on her feelings.
You said it yourself - you're a doctor. If someone you hate comes in with a gunshot wound, do you refuse to treat them or make it painful for them because they're an asshat, or do you fulfill your oath, do everything you can to help them, and put your feelings aside for the time-being?
I'm not quite a doctor yetBut that day will come
. And yes I would never refuse treatment, unless the treatment itsself were unethical. Nor would I ever harm a patient if it can be avoided. But I don't think Janeway was on a power trip. She seized a chance to get information so she could apprehend Ransom. Did she do this in a calm and collected manner? No, she didn't. She acted impulsively and I suppose that was an act of weakness. But going as far as saying she was reveling the situation is simply bonkers.
I don't believe she was reveling in it, and if I at any point suggested that I thought she was, that was poor communication on my part.