I think moving Kapanen and putting Bracco in that spot is a huge mistake. Everyone seems to be blown away by his AHL numbers this season but I don't think many have actually watched him. He's a good skilled player, but I'm not so sure he fits in long term with the Leafs. Of the 79 points he had this season, 40 of them came on the PP (8G, 31A) to which he led the AHL in powerplay points. That's a great thing, but to me it says more bad than good. He's an extremely good passer with great vision. He finds the open man and can quarterback a PP. But that's all with the puck that he shines. He's not that good when it comes to playing without the puck and he was only a +1 this year for his +/- which says a little to that point. Unfortunately with Toronto, Bracco is highly unlikely to see top PP unit minutes with Matthews, Tavares, Marner, Nylander, Kadri, Johnsson, and Kapanen all seeing time on the 1st PP unit this year who are all ahead of Bracco. So if Bracco can't be on the top PP unit, he's not going to get that much time on the PP which is where he excels and he might become a liability at 5-on-5 and he'll never be above a 3rd liner then as he won't pass Marner or Nylander at RW. It's hard to believe high in Bracco when i was only 1 good season in the AHL that he's had and there might be some other issues that don't allow him to fit into the Leafs roster long term. Personally, I'd use his value now to Toronto's advantage and keep Kapanen (you even have the cap space to do it) because Kapanen fits the role better of a third liner and someone who can play more than just PP time and he can kill penalties and play both RW and LW up and down the lineup.
I like the idea and think its very reasonable to get Colin Miller in Toronto and at a cheap cost, but it might cost slightly more than Holl who hasn't played much and doesn't have any value.
I'd much prefer to keep Brown and I think it is possible. That's more because of the role he plays and kills penalties and has a physical edge to his game. I think if it's only a 3rd round pick that they can get, I'd rather them move someone else that has more value to get a more significant return (I'm more thinking of Kadri being moved).
Everyone knows Zaitsev will 99% be moved. Requesting a trade helps Toronto but everyone knows about their cap situation so they'll have to pay to offload him unfortunately.
Free agents can be a hit or miss. I don't think Toronto will be signing any due to their cap issue. I like Stralman as a fit, but I think he'll get more money and term from someone else and Toronto just won't be able to fit him.
Final small thing, nitpicking a bit, but Hyman and Dermott will both be on IR to start the season, might be smart to adjust that and bring in 2 more players to fill their spots to have a better idea of the cap situation when they return.
Check out something I posted a little while ago. I made some very similar moves with slight changes but found a way to keep most of the roster together:
https://www.capfriendly.com/armchair-gm/team/1198695