This is the homeowner. You asked several questions my son-in-law cannot answer and your system won't let me make an account on your site because this account is apparently the only one allowed from my IP address. That system seems sub-optimal to me.
To answer you, first off...that GA address is the location of the Comcast Business PO box for receiving bill payments. The address below that is mine.
I work for a software company and am a huge tech guy. I have a business account because I need a static IP for several things I host myself from my house and it makes system administration for my job easier. Comcast, being what they are, doesn't offer a static-IP option for their XFinity (consumer) accounts. So between that and that I typically use more than 3TB of bandwidth in a month, the business account is actually cheaper for me. Not that any of that is really your business.
It is really common in Comcast-serviced areas for people to just sign up for business accounts at their home just to get around the bandwidth caps. I'm surprised you haven't heard of it before now.
If you want to discuss my personal life further, ask my son-in-law via private message for my email address.