Businesses of a different industry can use the same name. There is nothing keeping you from using the website for blogging. The computer store might be problematic if it could be construed you are trying to profit from EA’s established trademark. Also, why would you want a .org for a storefront? I’d say get a different domain for your computer store.
What do you mean actual jammer? If it puts out RF at a power level greater than the surrounding environment it is a jammer, correct? I would think for this attack to work you could just target the camera freqs used, you don’t have to target the whole home’s WiFi network. Probably a narrower range to focus on.