yes, u got the latest upgrade Chuck. Glad you're enjoying the 520.
Yes, u can delete excess channels but we've all had trouble keeping them hidden on the "custom" setup. After going through the process of deleting the unwanted channels, the 520 forgets and after a few days or weeks they all show up again. The "surf" list keeps them with no trouble though and doesn't have this trouble. You'll find the "custom" and "surf" lists on the left of the guide and can access either from there.
"4k UHD makes today a great time to be alive"