I could handle Timothy, but I wasn't able to find anything on Dylan.
Here you go. He played a villain (Prof Ivo) on the Arrow tv show. He worked well there as a psychotic yet still oddly sympathetic captor who was experimenting on people.
How about Anson Mount of Hell on Wheels for Michael?
Too..Hard. Michael is a tight-rope walk in that he needs to be a guy that can smile with his eyes alone and exude happy contentment while holding a baby at a little league game, while still chill your blood with a hard look and soft-spoken word. Mount could do the Warrior of Heaven but not the gentle Daddy side of the character, even when he smiles it just doesnt look like it quite fits on his face.
I could see him as a decent Slate or Kincaid, though Jason Statham is my go-to. He'd also make a dynamite Morgan, if Clancy Brown ever starts aging.
How about Colm Meaney for Gregory Cristos?
I think he'd fit the tone of La Fortier more. He fits what we all suspect is under the surface of Cristos, but not the public persona. Cristos projects himself as more of the Gilderoy Lockhart of politicians (maybe a hair less stupid). I expect whomever plays Cristos to be a little on the younger side (relative to the SC) and to have a blindingly white fake smile.