HOLY SHIT! I assumed he was in his low twenties by the way you described him. At least if he were young he could use the excuse that its just a "phase" but i guess he's a bit old for that. Honestly I think everyone has some sort of dysfunction. I saw a therapist after my dad passed and I thought our family was fucked b/c we fought all the time, even she told me "come have dinner with my family and you'll see your not alone" sure enough I sat at a dinner table with a bunch of stranger's yelling at each other, it was kinda funny really.
Anyway, I know what your going through with your brother. I have a sibling (older) who does the same shit. The world only revolves around them and how to better themselves yet they dont see that their stepping over everyone else at the same time. It made me mad for a long time then I just realized I cant change them. I still love my family regardless you just have to set boundaries. As in, if he ask's for money or ANYTHING money related just say no. Eventually he'll stop asking.