Jack is many things but I don't ever read him as sadistic. He could have shot Ianto point blank during Cyberwoman he didn't. Rape standing in, in lieu of that? I don't buy it. Especially not if you remember the line in episode one series one where he says he's never getting pregnant again. I always read that line as it having been something that was done to him against his will so no, I don't think he'd so that to someone else.

But then I don't see non-consensual sex/rape as his chosen form of torture either. And yes, Countrycide tells us he was trained in that skill. I'd like to think it was high tech torture mind you, maximum pain without marking the suspect. But Jack does like vintage weaponry so who knows...