The episode that really nailed down what a talented actor Jeri Ryan is was the time she had all those assimilated personalities surface and was switching back and forth rapidly, and the bit where the Doctor "took over" her body when they were in prison.
Both times, it was absolutely believable that someone else was at the wheel, and "Seven" wasn't there.
I didn't think she's gay, probably more pansexual. She had a pretty weird upbringing, if you'll recall, so her sexuality is more like "gender is irrelevant."
While I absolutely do not want to defend Rick Berman, I also think it's important to acknowledge that his brand of assholishness was not unique (and, frankly, still isn't).