You aren't compatible. I don't see why people need to devolve into calling her names (crazy) or you, whatever one wants to call it. I agree with the post that said you know what you need to do. So do it. She'll be hurt and freak out and drama... etc. But in the end you will both be happier for it. Listen to your gut and those red flags. Ask anyone whose been through a divorce and they'll *all* tell you there were flags but they (stupidly, cowardly) ignored them. Marry her and you are 99.99% guaranteed to become another divorce statistic. That, or one of you will give up something crucial to make it work, which is not better than divorce, IMO. Soul destroying those (I hesitate to call them) 'relationships' are. I speak from hard-won experience.
Good luck.
Second thoughts can generally be amended with judicious action; injudicious actions can seldom be recovered with second thoughts.
--Cyteen by C.J.Cherryh