Hey Chev Malibu,
I've been out of touch for a while so no response from me. I do know what a keep alive is and have extensive experience in this area.

Where I am coming from, is your keep alive will be feeding a ground to ALL Circuits via the low amperage fused line. Not just the few that you intended (i.e. radio), but rather everything. A keep alive is generally directly wired only to the items that need power to keep the memories active.

If you have the master switch wired to the ground and use a keep alive to supply a fused ground line you are essentially suppling ground to everything. If you forget to switch on your master and try to start the car, you will blow the fuse on the keep alive and your memory items won't have power in the future.