Thanks to everyone who helped out...
My Nexus 4 seems to have stabilized, I've been observing it for a couple of days and it seems to be entering the critical deep sleep phase with minimal battery loss.
To aid people who'll trawl this thread in the future, here are a couple of things that I think made the difference:
1. Using Deep Sleep Battery Saver, especially at night and when I'm not at home (i.e. not connected to WiFi)
2. I don't use data consistently, when I want to check something I manually turn on and off data
3. Though UCCW didn't show up as keeping my phone awake, after uninstalling it I saw an improvement, I'm not sure if it actually made a difference or if it's my mind playing tricks on me (shout out to one of the thread posts that pointed this out).
4. Avoid the Minimalistic Text widget altogether, it looks nice but it drinks down your battery.
5. Disable everything under Location Services, be warned though this will mess up your Google Now output as well as a bunch of other things.
Last but not least, even while using DSBS, switch off your WiFi, Bluetooth, NFC etc, manually when not in use.
Thanks again to everyone who helped out!
I forgot to mention, the improvement happened after the 1.8mb security update, I have no idea how much of a factor it is.