Guys i think you're wrong.
The "5 slots" mechanism isnt right: i often face more than 5 different cards in winning slots, and sometimes get pillars from a deck with just 7 pillars out of 30 cards (my flying weapons deck for top50).
So i know your mistakes, but dont ask me for the truth: i have no idea 
I believe it re-chooses the cards for each individual spin. The mechanics are the same, though.
As for pillars- I believe Zanz might have removed any restrictions at all from them showing up in the spinners based on the fact I win about 10 qp a night off rainbow decks- which are only about 1/3 pillars.
Yeah my assumptions were that it picked 5 different cards for each full "spin". Since you can only see 3 cards in a spin, it is impossible to know that the 5 card mechanism is incorrect.
That is a good point about the Quantum pillars though, my personal experience has been that I win those a fair amount also, and you are right that most rainbow decks don't have too high of a % of towers. However, on the flip side, if you ever fight mightyhat's rare farm (has ton of Time pillars) or Kahl1701's (at least I think it is his... the rare farm that has a bunch of Bone pillars), you don't seem to ever see pillars in the wheel which supports that the pillar restriction is still there, since you would see them very often otherwise.
Possibilities could be that either the "50" number was decreased significantly (though if there were the case, it seems like mightyhat/Kahl1707 deck's would be spinning you pillars more often.
OR as someone else suggested, it may be possible that due to a programming oversight that Quantum Pillars are not correctly being identified as pillars.
