I find it strange that more people don't object to the current system that encourages players to have all their soldiers carry primed grenades from the moment the mission starts -- in real life, you would never do something that reckless -- if a single soldier goes down, he kills the guys near him, and possibly starts a domino effect of explosions that kills the entire squad.
Also, why would anyone in real life set a delay on a smoke grenade? I would think smoke grenades should only have "pull pin" with no "set delay" (or "prime grenade") option at all.
Currently, it takes 50% TU's to prime a grenade and 25% TU's to throw it -- I would make "Pull Pin" take 10% and "Set Delay" take 40% -- this would allow a decent soldier to grab two grenades from their shoulder, pull their pins, and throw them, each turn, and not have to rely on pre-priming.