And yes, I know she was avenging Tara when she did that. I don’t care. Torture is evil.
And I forgot her attempted murder of Andrew & Jonathan.
Hey, I’m only evil in IMHO. Hereabouts I’m just a pretentious snob. 
But if you really want to audition, bring me the head of John Wells.
Hey, that reminds me…
All of your examples save the first two (one of which doesn’t count because she didn’t do it and it’s action, not thought, that makes one evil) were within a year or so of the events of Seeing Red and the last six were all following it so she wasn’t evil for “some years” beforehand, which was what I was questioning.
I otherwise agree with your characterization… Willow has an addictive personality and she was corrupted by her power.
Do you mean summoning satan to screw veruca?
Sorry, I don’t buy it. She lost her nerve, but she began the process. If I follow a woman home intending to rape her, but see a cop car sitting outside her home and thus decide against my original plan, I’m still an incipient rapist.
As to the timing issue…well, I was just naming events I could think of off the top of my head. But if you’d like, I’ll backpedal. Willow wasn’t outright evil, but she was certainly corrupt, and it wouldn’t take much to tip her over. Do you think if Kennedy, Xander, or Buffy gets killed, she isn’t likely to lose it again?
The problem with Willow is that she is charming, and she thinks she’s basically good: i.e., that the events of the Dark Willow arc were an aberration born of addiction and grief. That’s a copout. She’s more dangerous than Angel, and not merely because she’s more powerful. She’s dangerous because, unlike Angel, she doesn’t recognize the darkness inside her and she isn’t on guard against it.
The difference being that your plans to rape the woman aren’t motivated by grief, anger, and despair that she’s half-responsible for and that it was only the cop’s presence, not your conscience, that stopped you from acting on your desires.
She’s corrupt, yes, and incredibly dangerous but I personally would not characterize her as evil.
Yes.
It not so much that you’re the only one who liked, but that you’re the only one who stayed around to watch them. 
Really? Doesn’t she spend a lot of the last season terrified that she’ll lose control of herself while trying a spell (or doing the horizontal with Kennedy)? That sounds like a good deal of vigilance to me. Admittedly, it took quite a body count to knock that into her, but still.
Maybe it’s just me, but I never bought that Willow took responsibility for her evil acts. She always blamed it on her “magic addiction,” when in fact the magic was just the occasion, not the cause.