Very few times in hockey where no matter what you receive in a trade, it still doesn't make sense. To me, Patrick Kane is an example. I know his cap hit and term are monstrous, but in terms of production, hes up there with 87. No way 87 ever gets traded, and I get the sense that's the case with Kane too. Hes so good at what he does, he is not replaceable and I feel trading him is a death wish for the franchise. As far as cap issues, they could easily trade a D man, and Kruger is all but guaranteed to be a Golden Knight. Having said that, what you provided here, in a fair value sense, would work but I think you need two 1st rounders to pull it off.

The Hawks are still in "win now" mode. Trading Kane would not make them any better right now. Keith, Seabrook, and Hossa are getting older and the window is closing so it wouldn't be the time to trade a perennial super star for some young players.

Sabres fan here

Trade seems about right
U guys get a lot of talent, & big time Cap help
Forgot to add Girgensons to your lineup,
he could be a good 3C or play either wing

Alzner will cost st least 5mil per season, maybe more

Of course the Blackhawks aren't trading Kane in the prime of his career while they're also hoping to contend for a Cup again. However, it's fun/interesting to think about as a what if.
I wouldn't sign Marleau for $5M though. At 37, even though he put up numbers last season, odds are against him duplicating it. Plus, I think he's like Thornton where they really haven't been interested in playing for another team.