Rob - Yeah I would not recommend changing values like that either, and I was also hesitant about using the globals sample, but I’ve seen plenty of people using them.
Regarding the other values not being correct, you are right, but then again I never used them to be honest - I just needed to know the width and height and I do the rest myself. I just felt I was missing something because this config.lua thing is something I’ve seen raised many times in the past.
As for Corona (or rather Lua) having multiple ways of doing things I agree. I consider myself a reasonable programmer, but am new to Lua, and still learn new things all the time that makes me love it more and more 
@craig - I have this issue in some games, where I want pixel perfect control. What I do in this case is have no scaling mode, and for front ends and menus etc I wrote my own alternative to content scaling. It works essentially the same, but the difference is you can toggle it on and off, so I get the best of both worlds.