Stilts to keep the buildings elevated in a swamp

Why does a white-black land use such a blue-red associated set of mechanics (caring about instants and sorceries, caring about casting noncreature spells, looting/rummaging).

What exactly is going on in this set that makes it so an ability with in its cost requires the clause "Activate this ability only once each turn"?

EDIT: Seeing the rest of the cycle, I at least get the first part. Apparently this is a strict cycle like Sinister Hideout/Secret Passage/Silverquill Campus, not a loose one like Rivendell, Lilypad Village/Agna Qel'a.

Acknowledging that it's partially explained. Adding looting/rummaging to the list of draw-smoothing abilities of scry, surveil, investigate, boardcycling, cycling etc. seems like a logical next step. I'm still befuddle by the weird complexity of the cost/condition and how it relates to how this ability in a vacuum probably would be: ", : Draw a card, then discard a card."

The question is both, whether exiling a nonpermanent card and then delaying the looting until your next noncreature spell is a cost at the correct level, and also (and more importantly) what the whole song and dance of this even means. The weirdest part is that both encourage the same thing: If you use this ability multiple times, then you probably exile the spell you have cast for the previous activation anyway.

There is also the fact that usually draw-smoothing abilities on lands like the ones linked above are tools to give players something to do late-game (among other things, obv, but as a general idea) when they have more lands/mana than they know what to do with, but might be concerned with drawing too much land over the spells you really want. So a straight-forward mana cost to activate seems ideal. OTOH a similar ability that costs no mana, but only works if you still have more spells to cast strikes me as a questionable variant of the same idea.

Whether you actually want to push for this much noncreature play across all colors is another question, but one that is more tied to the environment.

This set is an instant and sorcery focused set, hence the choice exiling the instant or sorcery. I was attempting to create a flavorful parallel cycle to the artifact focused other side/reality of Tornipuch which has Inspired Bridge(after seeing Mutagen tokens, I've confimed that Cog tokens leave much to be desired, but that's a problem for Tornipuch: Grinding Towards Power).

The activation cost being tied to a theme of this set initially felt like enough, but you bring up the point that a vacuum effect would probably cost to activate. This makes me wonder if merely including the instant/sorcery requirement is enough and if a mana value of perhaps should be added to activate the ability.