So, you're bringing up many points; I'd prefer if we could stick to a few, but I'll briefly address them.

A) I claimed that a major factor in the 2007/08 GFC was deregulation. You countered that it was too much regulation, specifically mandatory lending to disadvantaged communities. That theory, floated by a few AEI (American Enterprise Institute) people, has been called "The Big Lie" by Ritholz, and largely rejected, I think. [1]

B) > a group setting out to deceive the public

I don't know what group or conspiracy you are referring to.

C) I'll address your contention that Krugman called for a housing bubble in 2002. I think that is wrong, when you look at his writing in context. Krugman's argument was as follows:

a) Under normal circumstances, when the economy heats up too much (inflation), the Fed raises rates and cuts off the excesses. b) This causes a typical post-war slump. c) That slump can be fixed by the Fed by lowering rates, creating a snap-back of consumer and business spending. d) HOWEVER, the slump in 2001 was not a typical post-war slump: Lowering rates did not bring back business spending. e) Therefore, if the Fed wanted to fight the slump with monetary means, it "needed" to engineer a housing bubble (and basically replace the .com stock bubble with said housing bubble).

Krugman didn't endorse the bubble.

Here's Krugman in 2003 decrying the housing bubble, and also noting that the "banana-republic policies now being followed in Washington won't just drive up interest rates; they'll probably generate a full-blown fiscal crisis one of these years.":

https://www.nytimes.com/2003/06/20/opinion/still-blowing-bub...

Here's Krugman in 2005 decrying the housing bubble and "signs that America's housing market, like the stock market at the end of the last decade, is approaching the final, feverish stages of a speculative bubble":

https://www.nytimes.com/2005/05/27/opinion/running-out-of-bu...

Here's Krugman in 2006 decrying the housing bubble, predicting its end, and saying that "If anyone is to blame for the current situation, it’s Mr. Greenspan, who pooh-poohed warnings about an emerging bubble and did nothing to crack down on irresponsible lending."

https://www.nytimes.com/2006/10/30/opinion/30krugman.html

D) > Krugman is a major believer in Keynes' demand-side economic theories.

Yes, Krugman is Keynesian, of course, and argues for stimulus via fiscal policy (taxes and spending) and monetary policy (rates and money supply), when and as appropriate.

And yes, if the economy is stalled because of lack of demand, and monetary policy is ineffective because the zero lower bound, then fiscal policy (spending) would be effective (thanks to the multiplier), even if the money is pumped into fairly inefficient ventures, as long as the money goes to people that spend it (rather than saving it). (So, tax cuts for the rich are not good.)

That is not to say that a Keynesian would advocate a less efficient over a more efficient stimulus; rather, Krugman was making the point that any stimulus (to people with high propensity to consume) is better than none.

[1] for example, https://www.washingtonpost.com/news/wonk/wp/2013/02/13/no-ma... or see https://en.wikipedia.org/wiki/Causes_of_the_United_States_ho... for an overview of the debate.