Yes, it could definitely be causing the “spinning beachball” that you’re referring to, but then so could any of your other software (in this situation, it’s best to figure out when the “spinning beachball” started and determine what software was installed around that time). I’m always extremely suspicious of anything that covertly installs itself (any legitimate software should at least be informative during the installation!) but I can understand your fear of messing around on the command line.

I’m not aware of any particular “risks” the Google Software Update poses.