Default Newbie question re rooting

I want to use an app with my s3 mini which requires a rooted device. I've not done this before and I don't want to tweak any other settings. I've read a lot about the risks of rooting, but didn't know whether the risks are associated with just rooting the phone or the tweaking of settings that some people do afterwards. I've seen an app called kingo that looks easy. Are there really many risks to my phone of using this and installing the app? But not installing or tweaking anything else?