[G 2014 General] rbmaster:
Auto = automatically, that's a smart feature, it adjusts the brightness of the screen automatically. Nowadays, the way it is programmed makes it way more battery efficient than before. Adjusting it at a maximum of 60% is just a guideline, but 60% auto brightness is not 60% brightness., the value is just a guideline for the auto brightness algorithm.

About the data always on, having data on doesn't require that much extra power, it only drains more power IF some application requests data. While not the most efficient solution, in Android Lollipop there's no better way to keep feature like auto.sync on without having the data always on, unless you have root access. If you have root access you can set up tasker to automatically enable and disable mobile data when the phone tries to auto.sync and/or when the screen is on.

As I said previously, this is a guide for everyone, no root access required, and the goal is to have the phone with as many smart features on as possible while retaining a good enough battery life. You can have all those features on and still have a good battery life, is it worth to disable most of the features of our phones just to gain a little extra battery life? I mean, if you really want to make your phone's battery last weeks just turn it off ^^'. Now seriously, I have auto-sync for all the features I need, I have location services apps all running fine, I can pair my Bluetooth devices just by turning them on, I can simply open the gps app in my car and it will get signal without me doing anything else, I can take a picture and immediately send to someone over the internet without having to do anything else, and many many other features I have that I wouldn't if I just turned everything off to get a little extra battery. Not worth for me, I want a smartphone, I want to take it out of my pocket and having it ready to use.

Follow this guide and check the difference in battery life it makes, than tell me if it is not worth. Well, for certain profiles I can see it not being worth, I mean if you use your phone primarily for gaming or if you don't use almost any of the feature a smartphone has, I can totally see the point in having them turned off.

Edit: Forgot to talk about the limited data plans. I have a very limited data plan, 500MB per month but communication apps don't have a limit on my data plan (facebook, skype, what's app, snapshot, etc). I never used the 500MB of the mobile data, when wi fi is available I use it and only transfer large files over wifi, so as you can see even 500MB is enough to browse the web and sync my services. If you don't have a data plan or yours not enough for you then you have to choices: 1- Get a data plan suitable for your needs; 2- Disable Mobile Data. Back to the guide, there's people too with limited data plans in their home connections, using wifi, should I tell everyone to have wi fi always turned off because of those people?

If your data plan has limitations, that's something you have to take in mind but has nothing to do with the phone itself. If I have no money for a vehicle, I have to travel by foot, should I tell everyone to travel by foot? I hope you get my point and sorry for the wall of text.