You raise many different points, so im not sure what to say exactly, but some things i think are important are the fact that the people that ran PRIDE are the ones that were responsible for its downfall with their involvement with underworld figure's etc that led to them losing their tv deal and so on.
That is where the real PRIDE ended, the faith of PRIDE as the company we know it was in the hands of Zuffa after that, it was up to them what path they wanted to take when they took it over, they didn't have to say anything about keeping PRIDE as it was etc, but thats what they did, and maybe that was their original intention or maybe it wasn't, but for whatever reason, they couldn't make whatever plans they were making work, you can say it's all Dana/UFC's fault that PRIDE as a company is dead, but when Dana says the Japanese staff were hard to work with etc you can automatically jump to the conclusion that he's full of shit and he never had any intentions of keeping PRIDE going in Japan, or you can take a step back and look at it impartially without all the pro-PRIDE feeling running through your veins and think maybe the people who managed to ruin the company in the first place might not have the best plans/future in place for an American company to come along and seamlessly enter a foreign company/market and go to town with promoting for their upcoming events, maybe they realised just how ****ed up the company/PRIDE name really was with the people that count like sponsors, financial backers, tv etc in Japan, that they said hey this isn't worth it and cut their losses and took what fighters they could and dropped the PRIDE fantasy.
We'll never know cause we don't know all the details, but i think it's worth looking at how big a mess things might have actually been behind the scenes that a company that is still building business in the States might be hesitant to start pumping money into. And to also keep in mind that the bad guys of the situation aren't Zuffa, but rather the many shady characters involved in the background/financial running of PRIDE that got them to the stage of putting blind faith in a foreign comapany to take things over.
You mention several fighters that should be in the UFC kind of matter of factly, but you have to understand that many fighters contracts were up and the UFC didn't have the automatic right to several key fighters (including Fedor, Aleks etc) and some were snapped up by K-1 etc.
But about the TUF/long stints between fights, thats a different story lol, and not a new one either.