With how good leafs drafting is looking I wouldn't move a 1st round pick and that does look like too much for Muzzin in my opinion.
I also think that 1st pairing is too offensive focused and that Vatanen isn't a good fit in Toronto, especially as you don't have him on the PP at all.
Ritchie is intriguing but his 50 or so games in the NHL have resulted in very few points and is already 21. I'm not sure if he will be able to score in the NHL like he has in other leagues.
Rychel has actually scored more points than Ritchie in 20 less nhl games and is only 1 year older.

That's a terrible trade for Muzzin. Giving up Gardiner and future 1st. With cap room, why not go the UFA or trade with team with cap problems instead of giving up so much, Why would CBJ trade two draft picks for Bozak who has one year on his contract......Maybe they should sign a centre Boyle? or someone else for 4.25m and they would be much better off. That's real weak LW without JVR and Komarov. The idea is still to win and get the team in the playoffs not to collect endless draft picks. Vatanan might be nice....but again with some cap flexibility maybe another signing would allow you to get your draft picks or JVR.
Leafs gave plenty of LWers upcoming who just as much potential as Ritchie.

The Boyle signing isn't so good because he's getting up there in age and he's declining, so it might cause cap problems 2-3 years from now. Good player (for his role) but 1-2 years would be ideal.

And Bozie is more valuable than just those two picks.

I said it earlier today and I'll say it again. The Leafs don't need another puck moving defenseman and one that's smaller than 6 foot. Also, that's too much for Vatenen, considering JVR is part of the mix. Ritchie is not valuable at all in my opinion and right now all the Leafs need is a big, stay at home, RHD to play big minutes for them, or at least someone who isn't afraid to throw his body around and intimidate the other teams.
Bozak is a mentor for the youngsters, whether that's valuable enough to keep him around, I'm not sure, but I can tell you the Leafs will wait as long as they can before moving him, and not for two second round picks that's for sure. I really like Muzzin, but Gardiner and a first plus Rychel? I don't think that's happening. And again, the Leafs don't need LHD right now. The pipeline is strong for the future.
I like Boyle as well, but as said above he is getting older, as if Dom Moore, so I don't see those signings happening for the Leafs, and it doesn't make sense to me to move Bozak and then bring in two - much older players, in the decline of their career who will more than likely find themselves getting waived - for more than the price of Bozak.

You are not good at drafting when you have top picks. I am fine moving some picks down the road that will be later 1sts if it is worth it. Not sure it is here.