Can I turn off Ability Tips?
Solution 1:
It really isn't about the tip, it's about showing confirmation button. I've spend considerable amount of time trying to figure out how to turn this off and found nothing.
However, whenever you're using keyboard shortcut, there is no confirmation needed.
Default bindings you can use:
Y — overwatch
R — reload
X — toggle primary/secondary weapon
B — hunker down
1 - 9 — abilities, counting left from right (annoying to use, as this constantly changes)
F2 - F11 — targets
Solution 2:
If you are playing on the PC version, just use keyboard shortcut 'Y' for Overwatch. IMO, pop-ups serve as confirmation on your decision so you can back out. Keyboard shortcuts are riskier especially if you are playing Ironman mode.