Definitely agree that sneak attack should be applicable to using special (single-target) arrows.
Yes,
surely now that the basis has been built, we’ll see something like the Divine Smite mechanic implemented that will let us apply sneak attack damage when any appropriate attack hits. As I know has already been mentioned by others elsewhere

.
I think the poison thing has a lot of merit as well. Right now only the Wyvern poison is accurate to 5e poisons. There isn't a poison that only does 1d4 damage.
Wyvern Poison (Injury). This poison must be harvested from a dead or incapacitated wyvern. A creature subjected to this poison must make a DC 15 Constitution saving throw, taking 24 (7d6) poison damage on a failed save, or half as much damage on a successful one.
Serpent Venom (Injury). This poison must be harvested from a dead or incapacitated giant poisonous snake. A creature subjected to this poison must succeed on a DC 11 Constitution saving throw, taking 10 (3d6) poison damage on a failed save, or half as much damage on a successful one.
Purple Worm Poison (Injury). This poison must be harvested from a dead or incapacitated purple worm. A creature subjected to this poison must make a DC 19 Constitution saving throw, taking 42 (12d6) poison damage on a failed save, or half as much damage on a successful one.
Drow Poison (Injury). This poison is typically made only by the drow, and only in a place far removed from sunlight. A creature subjected to this poison must succeed on a DC 13 Constitution saving throw or be poisoned for 1 hour. If the saving throw fails by 5 or more, the creature is also unconscious while poisoned in this way. The creature wakes up if it takes damage or if another creature takes an action to shake it awake.
Making these limited to rogues would be a good equalizer dps-wise. This should include the saving throws.
No doubt it will get modded in if not.
Also Poisons are only meant to usable with Slashing or Piercing weapons NOT Blunt weapons. So that also needs fixed.