Just a few things that may be clarifying, or maybe just confuse the issue further.
The breaking of A law doesn't destroy the concept of law, or all law...though if there aren't
consequences for breaking A law, the architecture of law is weakened. [What's that game? Jenga? you keep trying to weaken the structure till you force someone to make it all collapse] On the other hand, sometimes the consequences for breaking a law are not equal to the violation [if you kill my wife, no price you pay, even if it is death, is equal to the effects you have on the world by killing my wife]
The ceasure do pull things out of place/time, and weaken the Arch slowly, though I suspect if someone really essential was pulled out before they did the essential thing, it would all crash at once, but the ceasure just poke at time, being undirected, random not only in place but time over vast territory...and in some respects the ceasure are enforcing time as it actually happened (staff disappears in past because Linden got it...in a way, the breaking of time was not a breaking of time, but necessary because it happened in time...at least sometimes

] Powerful beings being present in the now and forward doesn't violate time because the now-forward hasn't happened yet (unless you change something/one essential in the past)...we already know that all prophecy in the Land is only truth-y, not truth. They are holistically right, specifically wrong. [Many predicted the downfall of British empire, they were all right, but even with hindsight no one can cite the precise reason...because there isn't one precise reason]
And for Spoonchicken's question: Elena expected Kevin to be MORE than he was in life...but he was actually LESS. The dead weren't 'resurrected', they were simply 'reanimated'...they had none of the power of will/choice/life, they could only be commanded/enslaved, and achieve those things they could have while alive [kill Elena? no problem, she hasn't 1/10th the lore Kevin had...defeat Foul? He never could do this]. And the power of command is like any power (or tool), if you misuse it, it's your fault, the consequences are completely unpredictable, usually bad, and the more powerful the instrument, the more people who pay the price.
("or whatever", he mumbled)