Hey, I know how frustrated you are. I am married to aguy who is a bit like this. Not his fault, really.... I've taken over the lion's share of the parenting, so things that seem "common sense" or "second nature" to me are just.... not, to him. Also, women tend to be better at this stuff. It doesn't mean the guy is stupid, or lazy or a crappy parent. Don't get me wrong, I don't know your situation fully, so for all I know he might be all of those things, but IMO, these "little" things aren't evidence of that. He's just less experienced than you at these "little things", and, well, he's... a guy!
It's a bit like driving. Driving is easy. Lots of not-very-clever people do it without hardly thinking. But when you first start, it's HARD. All the components of driving are "little" and "easy" - but gosh darn it there are just so many of them! I think the practical side of parenting (the bit mothers often do) is A LOT like that. Easy, little, obvious things.... but there are hundreds of them, and trying to remember them all at once is like keeping plates spinning, until you've done it all day every day for a long time... then it's second nature, and when someone else screws it up, it's too easy to marvel at how obvious/easy that was - how on EARTH did they screw it up?!
So here's what you DON'T do: you don't say a word about this to this kids. It can be SO easy to fall into the trap of "gah, your dad didn't do such and such again and I ASKED him to blah blah blah..." No matter HOW justified you are in saying it - DON'T. 
But, that said - say what you gotta say IN FRONT of the kids where possible. This will do 3 things:
1. It will MAKE you keep it short
2. It will MAKE you keep it "sweet"
3. It will make sure no one else (dad, his GF, WHOEVER) can say, "well your mum said...." or "mummy's being stroppy/mean/difficult". They really shouldn't say it, and I hope they don't, but like I said, when you are frustrated with a "partner", boy but it's hard to button it. Even more so for you both now, because neither of you can offload to each other, so the temptation to let it slip to the kids is there. So, doing it this way means your words will come straight from the horse's mouth (sorry!), and your
kids can hear them as you say them, rather than possibly hear someone
else's version of what you said.
Does this make sense so far?
Lists might be a good idea, I think a list tucked into the front pocket of their bag for daycare might be best. Ask the staff to check it off at X time - before he turns up. Tell him the list is there, but no need to tell him that they are checking it as well (because sometimes they may not have time, or he may come early and anyway, he needs to learn to do this easy stuff without you holding his hand now, right? Also, get the kids to check for themselves too - the littler they are the harder it is, but the sooner they can get the hang of it the better. With three people checking, he is less likely to get it wrong (one would hope).
Get on the good side of GF, so again, if you can say what you need to say in front of her, great. If she can see you are being polite and reasonable about things, then if he tries to twist stuff around and make out that you are the snake in the grass, it won't wash. The more you can all co-operate the easier for you.... and the better for the kids too.
I reckon this is pretty much the hardest scenario I can imagine, family-wise. There are so many pitfalls and so many ways kids can get hurt. Good luck, and boy but I don't envy you.
"Give a man a fire and he is warm for a day, but set fire to him and he is warm for the rest of his life." - Pratchett, "Jingo"
