It was a pretty fantastic 24 hours for the Celtics. I get beat up for this but IMHO, Avery Bradley is the only untouchable on the Celtics roster. (and maybe Jaylen Brown) Avery isn't an All Star but he does it all on the court. Unlike with Crowder and Smart, I don't cringe when he sets himself for a shot.
I would daft Fultz, and fully expect you know what you have after one full season, and then deal with IT next year. Decide if they can play together effectively, or decide if you want to move Thomas at his highest possible value. I'd sign Hayward. Then maybe trade the 2018 Nets pick for a 10+ rebounder a game player. (Andre Drummond, DeAndre Jordan...whoever).