Oh, things aren't great are they?
You say that he's an amazing dad. He might well be fun for your son to play with but I don't think that alone is enough to qualify him as an amazing dad.
You left him with your son alone for a week and came home to find that he hadn't fed your son proper meals and didn't keep on top of basic chores. When his heavily pregnant partner needed help, he wouldn't even lift him out of the bath. He didn't care about being at the birth of his son. A dad has to be responsible as well as fun. He isn't acting like a dad, he's acting like your son's brother. I don't think he'd have a great shot at full custody but I'm no lawyer.
The point isn't about whether he's a good dad or not anyway. He would still be a father if you were seperated. The point is whether or not he's a good partner. You need to decide whether you want to spend the rest of your life with this man, and if not, then how long you want to waste your time with him.
Another angle you need to give some consideration to is whether you want your children growing up seeing him treat you like this? I wouldn't want my sons to think that mum's job (and therefore women in general) is to clean up after men who don't help and get to sit around having fun. I don't know if you know the sex of you next baby, but I also wouldn't want my daughters to think that women have to put up with this sort of behaviour either. Relationships should be partnerships and I'd want my children to know that.
I realise that breaking up a relationship that isn't working isn't an easy thing to do and you'll know his good points too. But please, whether you do it by chucking him out or by putting your foot down, please don't let him continue to treat you like this, it's not good for you or your children.
I'm particuarly concerned about his lack of care about you having a bleed because you've had to do too much. He doesn't seem to care about his baby's safety or your health. Please take care of yourself and your babies.
Do you have family or friends that could come and help you with the housework and your son? You need a break.