OP, you need to get control. Now. And when he says "You're so controlling", simply reply "Yes, I am, they are my children and I would die for them, the least I can do for them is be in control."
Stop filling in fucking spreadsheets, it's ridiculous. If any solicitor asks you to do that again, report them to the Law Society. It is up to you how you spend maintenance. If you are providing your girls with a roof, food and clothes he has zero right to even ask what your spending your money on, it's harassment.
WRT clothes - the girls need to take control. It sounds as though he has someone on 'his side' (mother?) chipping away at him about what they wear ("trendy?") and he is too weak to say "I don't care what they wear, they are my girls and I love them" instead he is taking some kind of pathetic stand (egged on I would expect) and as a result dressing them up like twats. Poor girls. They're not dolls you know :( Talk to them about how they feel in those clothes and give them the permission and strength to stand up for themselves.
And finally, for all those saying YABU, you're not. Courtesy is not a big deal with your ex. BUT it will be a big deal to your girls, you are their mum and he is their dad. Is it OK in a stable home for the kids to see Dad constantly treating Mum like shit? Geez, you can't even pretend to get on for them. That's horrible. The most important thing children of separate parents need is permission from each parent to love each parent. By refusing to even be vaguely pleasant, he is making it obvious that he loathes you and doesn't even respect you. Can you imagine at 10 years old telling your Dad that you love someone whom he cannot even be polite to?
Now DS is 11 I get him to make a lot of the decisions (within reason and with absolute permission to favour either me or his dad). When I asked him how he felt about the doorstep handover (v. similar, not even a modicum of pleasantries), he said he hated it - found it so stressful, knowing we could row at any time. I asked what would make it better, he replied that he'd prefer dad to beep the horn and he'd go out. He does that now and he's much happier. I hate that, but I cannot speak to the man, he is a monster.
BTW I am not judging you at all, I have done all of this and it has taken me 9 years to get to a decent place with it all.