I would be willing to bet that all your noise and vibration is the plastic blower wheel and the motor is fine. If there's no visible warping on the shaft and the motor runs quiet just purchase a new blower wheel. Since it's plastic I would double check the new one before assembling everything.
What a crock that they make everything so cheap on an RV. I think the industries goal on RVs is to make it good enough to last the warranty and after that they're assured to make extra income on parts and repairs. What can I say though we all keep buying em ! LOL