That was a clever method for discovering seer's (and allomancers in general). But it appears the lord ruler was only as aware as everyone else of mehods to snap people, beat them close to death. Aint the final empire lovely =)
Anyway, had seen the first two quotes before, him very helpfully telling us that he can't tell us anything yet =)
Third one is interesting though. "this threshold on scadrial much easier to obtain" could mean quite a number of things. The most logical (and interesting) thing I can think of is that he has modified the people themselves such that their spiritual dna is more floppy. Um, no wrong word, more volatile, easier to change. Which, I think could have other more serious implications in the longterm. For a start making haemalurgy easier, and perhaps easier to perform non-fatal haemalurgy.