First off, I love Willow the way a brother would. Her actions, however, cross the line into sexual assault! Her conduct in season 6 makes her a villainess then. It was building for a while- that's the way evil works, people... it never makes itself clear until it thinks it's dominant.
From the First Evil's perspective; this is how you corrupt someone!
My views on her: I percieve her as a younger adopted sister of mine, and I love her in that way.
A lot of the posts here seem to be the perspective of the elder child in the Biblical Parable "The Prodigal Son", I percieve her as a 'prodigal child' too... but we also have to be merciful., sure she did horrible stuff: rape, attempted murder, theft, et cetera.
Look at it from Giles POV: his 'adopted daughter' does this stuff, he'll fight her, but he loves her at the same time.
It's sort of like you have an adopted sister who joins a 'gay gang', rapes someone, tries to commit murder, burglery, et cetera... all sorts of horrible stuff! What she really needs is you to be her brother or sister and just be there for her!
I think they did tell Kennedy, hey, Willow probably let slip that she did horrible stuff very early on in their relationship (Willow/Kennedy relationship), but Kennedy is thought to say "That's all in the past. I love you!",,, could be great fanfic fodder though.
It's possible that Willow was so shocked by what she did that she didn't even want to think about it.
It's also possible that the assaults were almost every night! We are only led to believe it's this once or twice.
I think most of the posts here are anger, rape is a profoundly wrong, hateful act... but those who do horrible stuff are still human (if they are indeed human- biology determins that, NOT public opinion), and must be treated like that.
Did Willow repent? I think she did. Why do I think that? Her remark that she is afraid that she may not be accepted back and that she may not be able to control it- it's the rush of power that's addictive to her, the energy, the strength, et cetera.
Her ultimate fear I think is that she will do the same horrors to another innocent that she did to Tara.
She's basically in a mental hospital at the beginning of season 7. I know what someone in such a situation needs: to know that they are welcome back home.
Maybe Joss Whedon is the sort of man who likes forgiveness stories; good for him! But Willow's acts do carry consequences: she lives in terror that at any moment, she'll go bad again, I know that terror of evil personally, I also know that there are ways to deny it influence.
It can be said that those who are caught are the lucky ones. (in the preternatural sense).
I personally think Willow's vice is lust- for girls, but lust still., doesn't mean she's sentenced to a life of badness though.
Mental-rape doesn't make any sense to me (definition-wise), but what happened in 'All the Way' was actual rape! (To verify, read: "Buffy goes Dark" essays on the final two seasons of BtVS tv series.) NOBODY SHOULD LIKE THAT! But we should be willing to forgive the criminal girl nonetheless.