You're using someone else's likenesses, though. You don't own Bill Murray's likeness, for example; painting it with your own hand doesn't make it okay to use it. I'm not saying you aren't painting your own work; I'm just saying that unless you have Bill Murray's personal consent to use his image, you can be sued or shut down.
Not trying to upset you, just trying to help you out. I'd hate to see you get shut down or sued like so many others have (it really does happen all the time). It's important if you're going to sell your wares, whether on Etsy or elsewhere, that you know and follow trademark and copyright laws.