What's that thing where the first half of a sentence is contradicted by the second half? Technically that post wasn't a single sentence but equally it should have been, because you can't start a sentence with "and".
So basically, what? If she's perfect, and you're perfect, then why not just go for it?
Look at it this way. Say you got leant a trampoline for 2 months, and you really, really wanted to jump all over that trampoline, but you felt so strongly about it that you were scared you'd miss it too much if you did when you had to give it back, would you choose not to, or would you spend every second of that 2 months bouncing about like a twat? Then you'd have 2 months of perfect bouncy memories, rather than always thinking "Why the f**k didn't I bounce on that sweet sweet trampoline when I had the chance".
In short, do it! Just don't make it a "relationship".
EDIT: Sounds like she could be crazy though... Crazy ain't fun. But then again, crazy generally is a lot of fun during sexy time.