OK, lets take these one by one:
1. Is it speculation to think that the pandemic office would have been prepared? What exactly do you think it's purpose was? Here is an article by Beth Cameron, who ran the White House Pandemic Office which President Trump shut down:
https://www.msn.com/en-us/news/opinion/i-ran-the-white-house-pandemic-office-trump-closed-it/ar-BB1192Xy
She writes:
In a health security crisis, speed is essential. When this new coronavirus emerged, there was no clear White House-led structure to oversee our response, and we lost valuable time. Yes, we have capable and committed global and national disease-prevention and management organizations, as well as state and local health departments, all working overtime now. But even in prepared cities like Seattle, health systems are struggling to test patients and keep pace with growing caseloads. The specter of rapid community transmission and exponential growth is real and daunting. The job of a White House pandemics office would have been to get ahead: to accelerate the response, empower experts, anticipate failures, and act quickly and transparently to solve problems.
There's a lot more. Please read the entire article and decide for yourself whether or not President Trump made things much worse by foolishly eliminating this office. There is no doubt in my mind whatsoever.
2. The report that Trump didn't want more testing is not fake news. It comes from a variety of sources, originally from NPR, which is hardly a disreputable source. Here is a summary from Business Insider:
https://www.businessinsider.com/coronavirus-trump-high-infection-rate-dent-reelection-report-2020-3
I believe this is true. But whether it is or not, what has Trump done regarding tests since that original reporting? The answer is: he has lied to the American public. First he said that anyone who wants a test can get a test. That turned out to be false. Then, on 3 consecutive weeks on 3 separate occasions, he stated that millions of tests were being made immediately available to hospitals that very week. Each of these statements turned out to be false. Then last week President Trump lashed out, blaming the CDC (from which tirade I suspect you got your information), the Obama administration, and the media. Finally today he stated that it's not his responsibility anyhow, he's "not a mail carrier", and it's up to state and local authorities to figure this out. If you regard this behavior as defensible in a time of crisis, I do not. It's complete utter incompetence.
3. This article correctly sums up the issue with the Army Corp of Engineers:
https://news.yahoo.com/fema-army-corps-engineers-still-145521365.html
It was Governor Cuomo's original idea that the Corp of Engineers could be used to quickly build temporary hospitals, including beds, which despite your statement to the contrary can be done fairly quickly. For the past 3 days including today, President Trump has agreed with Cuomo and pledged to use both the Corp and FEMA, but as the article demonstrates,
neither have received any instruction! At the moment they are just waiting around for orders. This is not, IMO, an example of deliberate bad behavior on the part of President Trump, as the lack of testing very well may be. It is, however, yet another sign of his gross incompetence, and part of the entire problem with his behavior here: he doesn't have any notion of how to lead. He expects the states to handle their own problems, and then he can take credit for it if it works, and blame them if it fails. His primary concern appears to be with his own reputation.
4. With regard to both masks and ventilators, things are moving slowly. As you correctly point out, there is some positive news with some private industries, particularly Elon Musk, willing to contribute, and the Defense department also playing a significant role. President Trump yesterday invoked a Korean War law which allows him to direct industry to manufacture these items. Yet he refuses so far to implement it. Medical experts called on him to do this over a month ago, but he won't do it probably because he doesn't want to piss off his industry buddies in the manufacturing world. The shortages are about to hit us big time and cost many lives.
5. And now we get to the crux of the matter. Trump hasn't ordered ANYTHING. After 2 months of downplaying this crisis, referring to it as a media hoax, stating it was completely under control, he reversed himself 48 hours ago and called for social distancing as a recommendation. Not surprisingly, a significant number of people, many of them his supporters who still believe it's a hoax, are ignoring him:
https://www.washingtonpost.com/national/coronavirus-deniers-outbreak-hoax/2020/03/19/46bc5e46-6872-11ea-b313-df458622c2cc_story.html
If Trump orders a lockdown, as the governor of California just did, the public WILL obey him. But until he does, many people won't. Trump has a responsibility to do this (his main one; he is sworn to protect the public) and if he does not, history and the American people will find him culpable for the deaths that occur.