Stock ROM/no ROOT here... SAME ISSUES
I have done literally everything that has been suggested and them some, and while my reception improved about half of the time, battery life is AT MOST 15-20% better, and even that is pushing it... Only maybe 1 in 10 times will I manually turn off the screen, am on WiFi 90% of the time, disabled a bunch of apps, only have 3 Widgets (FancyWidgets, Stock Power: WiFi/BT/GPS/Sync/Screen bar, and APW Calender; each on different screen). I have done everything else, yet I am extremely lucky to hit 8hrs before hitting my 14% warning. I almost always let it get to at least that warning before charging, and once a week I will let it get down fully (until it dies).
NO DICE. And I refuse to let VZW give me a refurb phone for one that I just paid full price for only 40 days ago, and they are giving me the run-around... I love, love, love this phone, but the battery is a PITA. I carry my charger as well as a USB-car-adaptor in my pocket everywhere, literally.