Rainbow,
I understand totally what you're going through. First thing's first...your roommate is an irresponsible person. They should have their half of the rent, when it's due.
Anyway, me and my fiance also have a landlord who is a mean, pathetic old man. I'm very scared of him too, as he has said some indecent things. I will never open the door to him, if I'm the only one home. He complains to my fiance that I should open the door for him...but that's not going to happen. He stares and oogles at me.
I'm sorry that you have to go through this . I hope your roomy gets the rent paid, soon.
Take care.