If it were just the pan and a few utensils I wouldn't really see that as a particular problem, much less disrespectful. However, it seems that's just the thin end of the wedge. OP, it seems that you are afraid that after doing all the work to get the qualification, you will not be able to make use of it fully because DH's needs take over.
It sounds like he's told you that you will have to fit around his hours rather than both adjust, he has the biggest room in the house, and he took the kids to an activity they'd only just done (was that because he wanted to go to the theme park, rather than kids wanting to go twice?).
It also seems that he does get his way, so it's a strategy that's working pretty well for him so far. His hours are long but not ridiculously so. Most of the 'extra' hours being in the morning - yet he's too tired to bathe and interact with his kids at night (it's a bit sad that he want to do those things, IMO). Yet he does seem to have time for his collecting and games and other things in his 'man cave'.
It really seems to me that this isn't about a pan at all, it's how you feel that your life and the kids lives have to fit around him. It sounds like you feel he's been holding his earning power over you for years Well, isn't that one of the benefits of you getting the qualification then the job? Someone is going to pay you for your time and skills so he will have to take some responsibility (other than monetary) for the kids you had together.
He's been used to having someone else to free him up to do exactly what he wants in the workplace and at home, now he'll have to change to take a more active role - depending on how much you're going to insist that you're not defacto unpaid home help on top of your other responsibilities, i.e. it's what you both should share (and want to do) together.