Creepy AF. Oh...that is hot. I give that to you, but also creepy AF!
I don't care how many people would be okay with this, but you guys are wrong. You might be thinking 'As long as she is protecting me, everything is ok. Right? I can handle this. She is worth putting that extra amount of care into her to mediate between her and the rest of the world.', or something along the lines, but you are D.E.A.D. WRONG. Yanderes aren't just people, that are super jelly and also super affectionately. They have a mental disorder. They are acting normal for several days (because their minds are working normally (define normal, but ykwIm) most of the time), but then next second something happens, that is triggers that part of their morals, that is a little bit different, and sends their mind on a little horror trip. And you come along. They totally go asocial. Ranging from insulting someone, over spilling a drink over somebodies head, to f*cking jumping them. You can't talk sense into someone, who believes their actions are justified.
Is their grooming topnotch? If they have at least a bit empathy, yes! Worth it? Hell, NO! Don't put your dick into crazy. If he wants to put you into a cage, fly away!