My only recommendation to you has nothing to do with the engineer, but rather keybinds.
During your fight with the centaurs, I saw you clicking on your grenade skills. This slows you down terribly. You would be MUCH faster using the number keys for your abilites. I know personally for me, 5-0 are hard keys to reach, so I rebind them to easier to reach keys.
I keep 1-3 on my keyboard. I put 4 and 5 on my extra mouse buttons (gaming mouse). I then move the 6-8 keybinds to shift 1-3, and 9 and 0 to shift + extra mouse buttons. I also recommend moving the F1-F4 skills to something easier to reach. I personally use ctrl 1-4.
Without mouse keys, you can use things like shift + q,e,w, etc to make your keys much easier to reach.
It takes some configuration and some getting used to, but once you get it down there’s no looking back 
Your video was very well put together, and you got the voice for commentating for sure. Keep up the good work!
(edited by Fangorn.7148)