His apartment is his castle and don't think that you are allowed to walk in and start imposing your own rules just because he loves to indulge you. If you don't live together, forget about occupying his closet.
Even though you two may be madly in love, according to his logic, that's no excuse to break some of his rules.
To you it may seem that his apartment is just a place where he stays and where you can accidentally see his different mementos from sports, however, his territory is much more than that for him, just like your apartment is sacred to you.
His place is his castle and don't even think that you are allowed to walk in and start imposing your rules just because he likes to please you. Or just because you're together.
Taking over his closet
It's totally ok to have some things that you need when you are planning to spend the night at his places, such as deodorant, toothbrush, or a tampon in case of emergency.
But if you don't live together, forget about occupying his closet! You can leave a piece of clothes but forget about sharing space until you start living together.
Cleaning and moving things
Even though many guys consider having a woman's touch in the household desirable and worthy of praise, be careful not to overdo it. Women's tendency to get fantastic ideas for the reorganization of the whole place during cleaning and moving furniture is not desirable.
You may think your ideas are better, but he set up the apartment exactly as he wanted, and he wants it to remain that way. As far as the cleaning is concerned, if you start washing, ironing, vacuuming, you could start to remind him of his mother.
Using his personal belongings
Guys won't considered attractive at all nor acceptable the idea to use his toothbrush, razor, towel or something similar, no matter how much he likes you, or how sexy he thinks you are. Honestly, why would anyone do that? Use your own things.
Control over the remote
Whether it is about changing channels or exploring his new PlayStation, he will see such behavior as a usurpation of something so sacred to him that you can't imagine. If you start deciding what you're going to watch in his apartment, he will start wondering what's next.