Update: Final Chapter (I hope)...
I was going to take the car to the dealer so they could test the battery insitu, but this time the battery wouldn't even take a charge enough to start, so I loosened the bolt only to find that it simply raises the bracket like an elevator, so my earlier worries about lining it back up upon reinstall were unfounded. (I wish someone would've told me!). Anyway bracket came up easy, battery came out easy and I took it to the dealer.
The service manager wasn't in but the service writer dude knew me as I spend waaay too much time at that dealership (buying trucks, not getting things fixed). I tell him they should have a ticket as I'd talked to the SM about the issue and he said to bring the battery in. The service writer, not sure if the battery can be tested outside the vehicle (tester needs to read computer info I guess) asks his buddy who has no idea who I am if this can be done and the clown says 'not if he expects the warranty to cover it'. Gotta say I had to restrain myself and I walked away to get the tech whom I know and whom I know halfway knows his stuff. He comes over and takes the battery, walks away and says 'I'll call you when the test is complete.' The 2 service writers were staring at each other with confused looks.
A few hours later the tech calls and says 'yep the battery is toast' and they found a new one that will be in the next day. He said they were backordered for a long time so he felt lucky we found one. I got the replacement battery and now I'm back in business! And yes both my old battery and the replacement have the 'Specifically Engineered for the Ford GT' on them. I couldn't see the logo on my battery while it was in the car as the carry handle was covering it up.
Also since the battery was bad it wouldn't have mattered if I'd had it on the tender or not. I drive my car several times a week so that shouldn't be an issue. I thought it was strange that it went dead after only a few weeks of non-use. Turns out it was! I am using a tender on the Viper though, since it sadly sits most of the time.
The end...