In most states, you can't just with hold the rent in lieu of repairs. If that was the case, then all tenants wouldn't ever pay the rent because they would say things need repaired all the time. Yes you will receive an eviction notice if you don't pay the rent, that is probably the law in your state. Don't just call the landlord and tell them what needs fixed, put it in writing date and sign it, give it to him, and keep a copy so you have proof in court. My tenants give me a work order, dated and signed, then when we fix/repair the problem, we have them sign our work order that it was repaired. Take time dated pictures for proof also. As far as the carpet, you should have noticed that before you moved in, when you agreed to rent the apartment. Also, you have no proof that a mold problem exists, except by word of mouth. You need to call your local health department or Code Enforcement office and have them test it. If it is indeed mold, then you have a legitimate gripe. Buy some draino and a plunger for the next time that your drains aren't working properly.