You're incorrect. You have one too many cap-holds (because you only need enough for a 12-man roster), and you only need 16.5 million to get a max player from another team. Also noteworthy: the 3rd year of Pablo's deal isn't guaranteed (according to hoopsworld), so you can let him go and save the 1.7 million. In reality, the team's going to look like this unless your salary data is more up-to-date than mine is...
http://www.hoopsworld.com/new-york-knicks-team-salary
According to this, Shumpert comes in at a little less than 4 and so does Felton. The third year of Pablo's deal isn't guaranteed so you cut him, and Chandler and Amar'e don't come back...
Melo: 24.1 Million
Felton: 4 Million
Jr Smith: 6.4 Million
Tim Hardaway: 1.3 Million
Shumpert: 4 million (he's closer to 3.7, but I'll round up). He can also be let go if that's the difference...
1st round Pick: 2 million
6 cap holds at 650k = 3.9 million
That puts New York at 45.7 million, which gives them about 14 assuming a 60 million dollar cap. What that means is all the Knicks would have to do is decide not to offer Shumpert and they'd get just enough space to sign anyone that isn't a 9+ year vet (In other words, you could get Kevin Love or Rondo if he comes back healthy and those are the guys you're targeting).
From there, you have 10.4 million dollars in expiring money (Felton and J.R.) that you could do something with or let off the books the following off-season, plus the exceptions and minimum deals to get by. According to the numbers here, it works...
Point being, the exit strategy was put into place by Grunwald when he made the Bargnani trade, because everybody comes off the books in the next 2 years. There's no reason to blow it up now unless somebody's willing to pay full price for Melo or take both Melo and Amar'e together without giving up a longer-term contract.