Wizardry will always require you to take a standard (or in some cases, swift) action to use it. Given the number of memorized spells you have and that you know exactly your number of limited slots per day, you'll always be able to do something useful in combat but you'll have to use at least some tactics as their number per day is set. It feels like those games where you have a set "mana" pool that recharges.

Chances are, alchemy will be used pre-combat or take up someone else's actions in combat rather than your own. Given how you can always craft more with time, you will want to be using it a lot and requiring the downtime for it; you play both preparation and short-term.

Enhancement may or may not take actions to use. Use-activated may mean blasting with a wand as a standard action. Or it may mean a wondrous item coming into effect during another type of action or when the bonus is needed. Alternatively, it could even be a crafted contingency or similar trap. In any case, you recharge few uses per day but have high pool of uses - you are going to play the long game and conserve resources... till the need for a nova comes up.