So I have been dating this guy for 8 months.
While it might not work out with the baseball player, it sounds like you aren't ready to settle down with the messy man. It's only been four days, so I wouldn't necessarily write off baseball man.
However, if you feel like you are truly settling then I say don't do it. I went out with a guy a couple of years ago that was just crazy about me. I wanted to want him, but I found when we were out, I was literally looking around at other men thinking, "I want to be with that guy." That's just not fair to him, and we didn't date long. If you read Lori Gottlieb's book, she doesn't advocate "settling" either. She feels that you should consider men you might not have considered before because you might actually fall in love with him.
I think the bigger problems are actually that he jumps at what his ex wants & his children drive you crazy.
8 months is exactly the amount of time it took for me to feel I knew my ex b/f fairly well, and the newness started to wear off.
Oh, I totally relate to the friend issue.
So here I am, still seeing the guy but much less.
I, personally, could not put up with that kind of situation. But everyone has different tolerances.