Wings accept, although I don't think the 4th and the 6th are needed. Zadina, 17, and 42 for the Cat.

Your theory is good. Replace 10m DeBrincat with 5m Bunting, who is likely to be a decent 2c alongside Norris. Then again with that much talent on the 2nd line the Sens might want to gamble with a lower cost younger player with some upside. Boucher or Greig might be worth the risk to save 5m and since both can go down still they can be replaced if they dont work out.
Hart might cost a bit more than that.

Hart will probably cost more since Briere doesn't plan on moving him unless he gets a haul.