[NonIndigenous]

This can't be generalised in my opinion... not really. There might be an edge of aggression the guy's voice... or he might be someone with a certain reputation amongst others that makes him somehow more intimidating to probably turn down I imagine. Also different people will simply define rape differently. Can't really say if something trully is rape or not... so to judge I think of there being a scale of 1-10. Applying that to your 3 examples:

First: 2 - putting ur hand on someone else's leg isn't rape, it just isn't, but it's itrusive and if the guy wasn't able to read the body language then he's pretty simple minded, but if he could read the body language and didn't care, well... that's what made me give it 2 instead of 1... but there's no sex going there really at all.
Second: 4 - it's kind of harrassing. She gave over in the end, said yes, but she didn't want to do it and did tell him that earlier. This could maybe even be a 5. And given that the guy is apparently her friend too... it's not somethin you'd expect, not by my definition of a someone who calls themselves a friend. Again, there are different types of friends... so this could go on and on.
Third: 2 - like the 1st example, nothing was said by the girl, you can't blame the guy for that. Although given he was her boyfriend he should have been able to judge in a situation like that if she wanted to go ahead.

All those examples are with guys "they knew". If it was a total stranger that approached it would get a higher score.

Yea... giving it scores is kinda primitive still, but otherwise I'd be here for hours debating this. If it is or isn't rape is not a yes/no answer. How the girl percieved it is not the only thing it should be determined by, especially if she didn't communicate it (for whatever reasons). I'm more inclined to judge if it was rape based on what the guy's intentions were and how far he was prepared to go to get what he wanted. Of course that can only be judged by his actions.