Root phone askings to update?

[lite blue]

I have done the half root, thanks idiots guide, and am running the rooted stock Rom and WiFi tether. All is good. For the last two mornings the phone has asked if I want to load an over the air update *******.6 . I have said no. Is this something I should run? Or will it destroy my root? While I am asking questions, is there any reason to flash the radio if I am running stock root or only if I use a custom Rom?
Thanks