In fact, I wasn't even aware that you could "waive" players in the NBA. I've heard of cutting guys and buying them out. Does "waive" just mean they cut him before his partially-guaranteed deal becomes fully guaranteed?
Any time a player is cut -- whether they're released, bought out, or amnestied -- they go through waivers, where every team in the league is allowed to submit a claim. A claim, in this case, means taking on the player and his entire remaining contract.
If a player is released, and unclaimed on waivers, his contract is paid by his original team (with some caveats), and he becomes an unrestricted free agent.
If a player is bought out, and unclaimed on waivers, his agreed upon reduced contract is paid by his original team, and he becomes an unrestricted free agent.
If a player is placed on amnesty waivers and is unclaimed on "normal" waivers, then he goes to the team that puts in the highest "bid" on him. Only teams with cap space can place bids. If a player makes it both through "normal" waivers and amnesty waivers (which is actually run concurrently), he becomes an unrestricted free agent.
Then doesn't that mean (like Yogi suggests), if we somehow signed Pierce for the MLE, we'd have Pierce's 5 million stuck on the books (his partial-guaranteed money) + the MLE amount?
That's exactly what it means. The $5 million would be untradeable ("dead money"), while the MLE contract would operate like any other contract.
And further... does any of this matter? With Bass making 7 mil, Lee and Terry making 5 mil each, Jeff Green making 9 mil, Rondo making 12 mil and KG making 11 mil... aren't we over the cap regardless of what we do with Pierce?
Pretty much. For some scenarios, see here:
http://www.celticsblog.com/2013/2/14/3988242/cap-questions-could-josh-smith-replace-kg-and-pierceSo really we're talking about potentially saving 5 million for a team that is already like 20 million dollars over the salary cap? What difference does that make to the fan?
It can make a pretty big difference in terms of luxury tax. It's going to be more punitive this year, and becomes especially punitive in the future for repeat payers.