Tried this build, thanks for posting, it's working pretty well.
How are you calculating 2d6 from sneak attack? I'm only getting 1d10 + 5 + 1d6. Doesn't 2d6 unlock at lvl 5?
Also, although the range for superior darkvision is 24m, the range for the heavy crossbow is at 18. Doesn't make sense that heavy crossbows/longbows have the same range as their lighter equivalents, but that's the case right now, so you can only have advantage up to a range of 18m.