I think your distinction between "being friends" vs. "being friendly" gives you a guideline.
If you are in any way, shape, or form thinking that "being friends" is the way to "get her back", I'd say to walk away from that line of thinking. Because then what you're doing is a tactic. It's a method of trying to control the situation to your advantage. And it very likely will not work.
(Notice how the more you've pulled away and not allowed her to hurt you so much she is suddenly playing the I want to be friends card? That's because she's losing her punching bag and wants it back. I don't think for a minute she genuinely wants to be friends. She gets off on hurting you; she's shown that a billion times).
You've also already said you can't go this route without opening up to all that hope again. You already know what hope gets you. It makes you focus to an absurd degree on every single little nuance of her moves/words. It gets the focus on her and not on you. You struggle enough with keeping the focus on you.
I think you have your answer here, plain as day. The only way to take care of yourself first and foremost is to focus on you, and to do that, the most you are capable of right now is being "friendly." Treat her like she's a business associate only.
I'm 3 months away from the initial bomb and I had a 6 month relationship with someone that was very meaningful that is now over, and I'm single again. I'm probaby the happiest with me I've ever been right now and the most "over" things I've ever been.
I no longer want my XH back at all. I am a different person and I don't find myself attracted to the person he has become. We really have very little in common other than a shared history.
As a result, I contacted him a few days ago. I've not spoken to him in a year. I contacted him to catch up. He's responded and we have had a civil, friendly conversation. I think this is good. But I have zero hope or wish to reconcile with him as a mate, and honestly, there is a part of me, a very small part, that thinks I might be able to be friends with him again some day, but I still recognize that it opens up a lot of possibilities for hurt, and to what end? I've got tons of friends who haven't betrayed me and treated me like dirt. So even for me, and I consider myself more "over" my ex than you seem to be, I'm still sticking with being friendly only.
I think you open a HUGE can of worms if you attempt a friendship at this stage.
Let her get married. Let her crash and burn.
M45 Bomb 6/09; EA 6/10; Divorced 1/11 Proud single mom of 7 little feline girls and one little feline boy "Fall down 53 times. Get up 54." -- Zen saying