Janeway and Seven were totally a couple when they had their fake personalities and memories in that holodeck world. Before that, I think it was implied pretty strongly that Seven was a virgin. I think once she hooked up with Chakotay there was subtext of it being her first time, but then there was that wonky Unimatrix world too.
I do think that Janeway would've come down pretty hard on anyone who she percieved as taking advantage of Seven. The Starfleet crew should be overall morally superior to the average 21st century person since they'd go thru all kinds of psych screening and had been raised in a utopian society, so presumably they'd have enough morals not to take advantage of Seven in her early years. Who knows what the Maquis would be capable of though.
I do think that Janeway would've come down pretty hard on anyone who she percieved as taking advantage of Seven. The Starfleet crew should be overall morally superior to the average 21st century person since they'd go thru all kinds of psych screening and had been raised in a utopian society, so presumably they'd have enough morals not to take advantage of Seven in her early years. Who knows what the Maquis would be capable of though.