[Lazy_Perfectionist]

In multiplayer, diplomacy is involved, and my research is often decided by my opponents.

Destruction is good for Ulm's flails, yeah, but if you a low-prot, chaff-heavy nation like R'lyeh to wage war, Blade Wind is great. Destruction's generally more versatile, though.

In the early game, I won't go beyond four just to counter a specific opponent. In the mid game or an overly long early war, I'll consider going from 3/4 to six just for one opponent.

I generally get the essentials for my race up to level 3 (site seeking, earthpower, for instance) and then focus on a school of magic that gives me a lot of options and/or dovetails with a specific strategy (yomi - darkness, ma agartha earth blood deep well with lots of golems). I deviate every now and then to get a lesser school up to two, or counter a specific opponent. Or, I focus on the essentials, then focus on the basic spells. For instance, I want at least Attentive Statues to be available for MA Agartha before I waste time and gems on remote site searching.