Would putting on a pod filter or messing with the air intake help with acceleration??
Maybe, but not going to be the mega increase you are hoping for. Tuned right, it could help you with top speed and acceleration slightly if you've geared the bike to run at power peak rpm.
With no tuning, you probably make it harder to idle when the weather is cold. It's potentially harder to set a carburetor mixture too once you huck the stock airbox. Usually the engineers calibrate the intake and the carburetor for a certain amount of tumble and turbulence to help atomize the fuel during cold starts, idling, and low speed pickup. For the size of engine, the stock intake likely allows enough airflow to meet maximum power and usable range.
In the wet, you may even pick up too much water in your carburetor. We had to pull over once so our Ruckus ride leader could empty out his carburetor float bowl of excess water. You don't want to be that guy.