Monster Creation: situational attacks and CR

[raidou]

Should special, situational attacks, such as sneak attack or smite, be factored in when calculating how much damage output a monster is capable of for its CR?

Or do these situational attacks exist outside the expected range because they might not come into play?

How about feats such as power attack or deadly aim? do these get counted as part of the creature's potential damage output when assigning CR?

Thanks for any thoughts you might have.