Reasons why the computer will not cast the spells you script

[Tuna-Fish]

Originally posted by Norfleet:
A unit with a NORMAL level of quickness, that enables it to take only two actions per round, will follow its script, and burn through it 2x faster.

A unit with quickness that allows it to take *3* or more actions per round will take two actions out of its script, then perform the rest of the actions of the round according to the "final" command like Attack, Spells, Stay Behind, etc.

How exactly can you get over 2 actions/turn?
iirc, there are 5 ways to increase amount of actions:
1. Spell quickness (+1 action)
2. Boots of quickness (+1)
3. W9 blessing (+½)
4. Spell quickening (+1)
5. Champion trident (+1)
What all of them stack?
W9 blessing and the Trident stacking with quickness would make sense, but do boots of quickness and the spell stack? What about quickening? Do they ALL stack?
And when they stack, is it just adding or multiplying? (ie boots & spell = 3 actions or 4?)