Maybe replace Favored Enemies with Skill focus feats or Skill mastery abilities (First Favored enemy = Skill focus. Second Favored enemy = Another Skill Focus bonus or skill mastery with the skill the previous Skill focus was applied to, etc)? Not quite the roguish skill monkey, but REALLY good at what they do.
Pushing my own houserule (repeatedly

), but I modified the Iaijutsu skill to make the ranged ranger more deadly (actually did it for the IK scout, since I don't use the ranger). Pretty simple: Can only be used with a ranged weapon (bow or crossbow), can only be used on a surprise action (so only one attack), and your flatfooted while you aim. You roll the skill to determine extra damage (10-14= +1d6, 15-19= +2d6, etc. Damage caps at +9d6), then you roll to hit. If you hit apply damage. Max range of this skill is the max range of the weapon you're using.
This damage doesn't stack with sneak attack damage.
I do like the idea of swapping spells for favored terrain