You brave, brave people persisting with nap-time routines! If we're home I just sit really still and let him sleep on me! (I bet the cm/nursery will love me for that habit!).
Though I have enormous sympathy for those with difficult babies. Please remember that it's not you, it really is down to the baby's personality. DS1 was very high needs still is and having a happy, easy DS2 has highlighted just how difficult DS1 was. He has got a bit better as he's got older. Hang in there, and don't blame yourself.
FTM, the recommendation to make up formula with hot water has been around for a while, I think it's just the reasoning that's taken years a while to filter through. Formula milk powder is a wonderful growth medium for both babies and bacteria, so as soon as the tin is opened its no longer sterile. So the powder must be heated by adding hot water initially.
To batch-prepare, you can add a small amount of HOT water initially and then bung bottles in the fridge. Then add hot water (to now cold bottles) to top them up and warm them up as needed (not sure how long they can be kept made up, but I imagine enough for a day/night will be fine). For going out, you could take powder and hot water, or ask for hot water from cafés? Or you could pre-make as above and take out the cooled bottle in an insulated bag?
Or (as I'm half planning to if need be) use ready made stuff. (I haven't thought about the cost implication yet!)
I seem to have forgotten how we made the logistics work last time. I'm convinced I had magic boobs that managed to feed him morning, evening, overnight and all weekend. Yet also have vague memories involving formula powder. 