NAH; I get where you're coming from and it does seem like this was something that needed to happen so his lack of contribution would be on the table as an issue. Q tips seems silly but now at least you all have an opportunity to clear the air.

Him not contributing would technically be a discussion between him and your parents since they're the ones covering everything but with him taking your stuff as his own, it's obviously your problem too.

Talk to him. Talk to your parents-both of them. Make everyone understand how frustrating this is for you and that there's no reason why he can't help out more or at least respect your boundaries. Maybe take the opportunity to give him and your parents some benefit of the doubt too. They might not realize the extent of the situation and I don't think he's doing anything deliberately. Just being an annoying brother.

Ultimately, unless he's really willing to change things, it's up to your parents to enforce some rules in support of you. And if they don't, start thinking about moving out where you have the freedom to be yourself and have your own things left alone.