The discolor dark brown and black is most likely not mold at all. Probably just water stains. Even if it is mold, only a small percentage of mold is toxic. (less than 1%) I’m not sure who told you that if mold is discovered that your landlord is required to put you up in a hotel. That isn’t true. In most cases you will be entitled to rent abatement for the days that the unit was uninhabitable. (not required to pay rent for those days)

I know this sounds backwards, but if you really want the repair to be completed; you first need to bring your rent current. Even though your landlord can’t evict you over a repair request, he can evict you for non-payment of rent. I would think that your landlord would want to protect his property and fix the water leak regardless of your late rent situation. BUT, maybe in his mind he may not feel that it is a very big deal and may think that you have no right to make any request due to your rent being late.