Yes… this why there is a Mask of Water Breathing in the very first year… 
I have to agree with the general sentiment here - What you are essentially asking is “Hey, can you validate/canonize my headcanon.” I’ll repeat these two lines:
Head-canons are 100% more than fine! However, it’s not necessary to run head-canons by the original author. If something isn’t mentioned in a story, that doesn’t mean it can’t exist. (Though, that it can exist also doesn’t mean that it does.) If you want to tell a story using your interpretations, no one would stop you.
‘Head-canon’ and ‘fanfiction’ have been kind of buzz-words, but I think it’s important to realize that all they really mean is that it’s not official. And even if you run every element of a fanfiction by Greg (which, don’t), the fanfiction itself wouldn’t be “official” - and that’s okay. It’s okay for us to tell our own stories. Even at that, it’s okay to diverge from what ‘canon’ says about the story, just as much as it’s okay to try to adhere to it as closely as possible. You set the rules for your own creation.
(Also, Greg hasn’t posted for almost half a year.)
Also in regards to focus – Many powers need you to maintain concentration 
Couple example quotes: