Some RFA's I could see not tendered qualifying offers or preemptively traded:
Matthew Tkachuk- A near certainty they sign him, he defines their identity, but his QO is $9M and paying that to a winger who has only broke the point per game barrier once in his career is a bit tough to swallow. Personally I wouldn't pay him this much.
Brock Boeser- Boeser's QO is $7.5M and he only got 46 points (71 GP)
Dominik Kubalik- $4M QO and had 32 pts
Dylan Strome- His point totals were more than adequate to justify his $3.6M QO, but the org never seems too happy with him, likely cause of his underwhelming defensive game and occasional disappearing act.
Miles Wood- $3.5M QO and was injured all year, a bit risky to re-sign at that price tag without watching him play post injury. I'm guessing the agent will be fine with negotiating a lower salary, but he could likely force UFA if he was so inclined.
Ethan Bear- $2.5M QO not an outrageous QO by any means, but a price teams generally don't pay for players they healthy scratch for a substantial chunk of the season.
Ondrej Kase & Pierre Engvall- nothing outrageous about these QO's, but they are arbitration eligible and Toronto has higher priority holes to patch without a lot of money to do it. Though they would likely have the money if they bribe someone to eat the Halak contract.
*Obviously if the player wants to stay they can negotiate a deal below their qualifying offer which does happen semi-frequently.*