Wondering for playing rock, metal, and a little bit of everything with alot of playing time each day what strings would be better? The Elixir Medium Nanoweb (Gauges: 11-14-18-28-38-49) or Elixir Light Nanoweb (Gauges 10-13-17-26-36-46)??
Well thicker strings are less likely to break, them being less feeble. Also the 11's will give you a bigger sound, as well as nicer playability IMO. If you ever want to downtune the slight increase in tension with the 11's will also benefit, but downtuning too much will still be quite slack.
I say 11's. When you want to play in Drop C it'll be much better.
Let's go back to five billion bpm and see how good i am.
IMO, just get ghs boomers and dry them off with a cloth after everytime you play. That way the strings last much longer. The elixirs has less tone than normal strings because of the thin latex layer they use, well that's my experience. Going back to ordinary strings again was like... "wow!"

The best string tension/tone/playability balance you'll get with .010 strings in standard tuning. Go up a step in thickness for every semitone you downtune. 011 i Eb, 012 in D.
I used standard 011 set when I tuned my guitar to a D, but the strings were a bit flabby I thought.
If you downtune your guitar really low, and don't get enough string tensions - you will end up with a flabby sound.
For really low tunings, I would rather use a 7-string.
012 strings in D tuning sounds great though!