The only other thing that I would add to this is next year's FA market. While I won't claim to be a salary cap expert, this is my current take:
If they don't trade, in the summer, they have a salary of $35 (all salaries in this post are in millions) guaranteed (Duncan, Parker, Green, Leonard, De Colo, Joseph). They have Qualifying offers of $4.9 to Splitter and $1.1 to Gary Neal. They have Bonner guaranteed $1 . They have Diaw's Player Option at $4.7 (which based current play, I think he will take up), and Patrick Mills PO at $1.1. They have cap holds of 7.5 Million for Splitter (more than his QO), $19 for Ginobili, $15 for SJax, and $2 for De Juan.
Best case, assume that they take their time about signing splitter (Cap hold 7.5), Dump De Juan, Neal, Bonner, Mills and Sjax's rights, and re-sign Manu to a cheap $7 salary. Add .85 as the cap hold for the 30th place 1st round pick, and they are at $56 committed. The Max salary this season (12/13) was $58, and will be <$60 in 13/14. They will not have cap space to bring in an FA at any number greater than the MLE.
Trading Sjax for someone expensive (say < $11 ) will still leave them space to work under the max salary, assuming Splitter signs for something sane (<$11 say)
Parker $12,500,000
Duncan $10,361,446
Diaw $4,702,500
Bonner (Buyout) $1,000,000
Splitter $11,000,000
Green $3,762,500
Leonard $1,887,840
Nando De Colo $1,463,000
Cory Joseph $1,120,920
Traded for Guy $11,000,000
1st Rounder $850,000
Manu $7,000,000
A total of $66,648,206 would give us 11 bodies, and $4 Million to spend to fill up to 4 slots. We would have the Mini MLE, the vet min, to work with. Assuming the guy we trade for is good, I like this scenario quite a bit better than having the full MLE to spend.