No, it will not. If you have gas smell in cabin it means that the gas line is leaky. And you better find that leak.
Depends on what the smell is? Can be many things including mildew or mold in the HVAC system.
Get a new one.
If the air conditioner is being stored in a cool, damp place while not in use mold and mildew might make it's home inside. If you're allergic to such things, turning it on could fill your house with sickening mold spores. Dismount the air conditioner and sanitize it.
Any time an air conditioner smells I tell people to try changing the in cabin air filter. most cars its behind your glove box and not costly. good luck.
== == * There is water sitting inside the AC unit that is not draining out properly. The water is from condensation pulled out of the air. Check the drain to the AC unit and clear the clog. * There could be mildew on the fins of the condenser (looks something like a car's radiator). Try spraying an anti-mildew spray (such as Lysol), directly on the fins. This should clear up the unpleasant smell.
A smell coming from a reverse cycle air conditioner may be a signal that the filter needs to be cleaned. A smell like engine exhaust might be present if the air conditioner motor is in need of repair.
It's probably mold. You can buy chemicals that are added through the intake that might fix it.
change the cabin filters
The holes allow the smell to escape and so the clothes will not mildew.
Mildew or other fungus growing underneath it.
The mildew smell is probably from your carpet not drying. Shampoo the carpet again using a product that removes mildew, making sure that you remove as much woisture as you can.