I hadn't thought about crits. That is true. If you crit and THEN pick Smite Level 3, that makes a huge difference as opposed to picking Smite Level 1 and then getting a crit and wishing you HAD picked Level 3.
Maneuvers aren't wasted if you miss, so picking them beforehand isn't that big of a deal except, again, with crits. So I do see your point there.
However, it is very annoying to constantly get a popup with my paladin every single time he strikes an enemy - especially after getting 2 attacks per turn.
As for Sneak Attack, I'd like a toggle, tbh. Pick which attack you want to apply it to, and it just auto-applies it every time to that attack. Toggle to Off Hand and it'll apply to Off Hand. Toggle to Main and it will apply to Main - whenever conditions apply that is.
I'm not sure what the best solution is for Smite and/or Maneuvers, but I do see your point about Crits. Also, if an enemy's health is relatively low, and you think you can kill them without Smite, you may want to just NOT Smite if you rolled a Crit. So like, if the mama spider has 15 HP left, and you roll a crit with a greatsword, you have a good chance of dealing more than 15 damage with 4d6 (let's say strength 16)+3. So why would you want to waste something like Smite when you'll probably kill her with 4d6. However, you might want to use smite if you did a regular hit and only get 2d6+3.