The crediting they eventually used is pretty standard, I don't really think it's a problem though. People are too uptight over credits to start with.
But the rest of the stuff... basically sounds like the studio existed purely to extort publishers. People talk a lot about predatory publishers but here we have a predatory developer. Beware of the impending kickstarter.
First, I'm not at all supportive of credit fuckery - credits are important to workers. Because of behavior like this in Hollywood, there are now credit guidelines written into union contracts. It's not just about having the personal satisfaction of getting your name in a shipped product, it's about there being an accurate record of who actually worked on what.
I think if you worked on the game for three months or more, you should get a full credit. Bringing work politics, hurt feelings, etc. into it is extremely unprofessional and petty, and this almost always originates from the upper levels of the company. Basically, the threat of losing a credit is just another way for bad managers to pressure and control their employees instead of actually managing them effectively.
And, again... it sounds like SK was worse with this than most. But pretty much all studios fund other projects with money from their current project. Many studios invent reasons to artificially extend deadlines to bridge them to their next contract, too. And the marketplace almost requires developers to low-ball on the initial contract just to sign
something, with extensions as problems or unforeseen costs or difficulties arise.
It's a rough and competitive industry and these sorts of contractual perversions are the natural result of that. I'm not saying it's right or good, but it's common because 1) most studios aren't value-added studios, meaning that quality-driven studios are competing against them 2) most publishers can't actually perceive, let alone make themselves care about, quality, and 3) they naturally want to get the games done as cheaply as possible.
Also, BTW, friends of mine that know Denis say he's got a serious reality-distortion field going. It's basically the way he's been able to keep at it as long as he has, but the last few years of SK's actual reality have made people wise to it. And I think Denis' recent antics just show that he bought into his own bullshit years ago.