Yes, there's definitely a software bug causing drain issues. No, you're NOT paranoid. It will be easily fixed by a software update, of this I have no doubt.
It's not NFC. It's not background Apps. Sorry to disappoint those benefiting from a blatant placebo effect, but it's true. I've been testing all week (and have posted on the Bugs/Defects thread on the matter). A soft reboot of the phone will "fix" the issue for a while, but the effect seems to be that the radios are shutting down or going into low power states properly, hence why rebooting fixes it for a while.
It's also happening on the 8X too, and the details too specifically match what we're seeing... 10-20% loss/hour (depending on usage during that hour), like clockwork.
For example, here's a summary of my own experience this week. I was traveling from Youngstown, Ohio to Lafayette, Indiana on a business trip. I used GPS (Drive+) for the entire trip over on Sunday as well as navigating around on Monday and Tuesday. Absolutely NO issues whatsoever the entire time. No Google accounts, NFC on. Wi-Fi on but not connected. Bluetooth off. Location services on. Skype and Facebook chat logged on all day.
Wednesday based on forum reports, I made some changes to test. That night I went to see Wreck-It Ralph. My phone went from 100% to 76% over the course of the movie, but NFC was off and so was Location services and Bluetooth and Wi-Fi. I was on LTE data. I had NO apps running and had explicitly blocked all background apps for the evening to see. Curious, so I let it charge back up overnight.
Thursday, I had the drainage issue all day. Off the charger at 7:30am precisely, and by lunch it was down to like 65%, and by 5:00pm it was down around 30%. At 7:30pm, I went to dinner and it completely died on me. Around the 12:30 mark (after lunch), I put the phone in airplane mode and enabled Battery Saver with only LTE data enabled and shutdown all apps. So at that point, it should have been doing anything. When I put it back on the charger at 8:00pm, I rebooted, re-enabled everything to normal states.
Friday morning at 6:00am, I left Indiana to return home. Now I kept it on the car charger for the ride home, but obviously it rebooted from the shutdown on Thursday night, and I used Drive+ for the ride home. I took it off the charger at 12:10pm when I arrived back home, and as of midnight last night when I went to bed, it was only down to 67%. In other words, it was back to normal.
I did use Drive+. I had NFC enabled. I had no Google account on the phone. So again I say, either power management in WP8 has a nasty flaw, or the batteries really do just need a full drain, recharge, and reboot... that latter of which seems unlikely given battery technology.