Ok, but those books and reports are all from people willing to trashtalk Trump.
The reason so many people are willing to trashtalk Trump is that his administration is leagues ahead of any administration in decades for its dysfunction, chaos, corruption, and the sheer ineptitude of the president himself. The very existence of those books is a warning, never mind their content.
Your argument here is essentially that Trump is an ignorant and easily manipulated child - the only logical conclusion of which is you're making an argument that he's not unfit to hold office because he's unfit to hold office in a different way. That is how bad it is and what your "defence" of Trump has come down to.
But it's not even true. Trump is absolutely not the sort of bumbling tabula rasa, waiting to be imprinted, that you portray him as.
He's a narcissistic monster, and I really mean monster. Narcissists such as Trump are not some sort of reasonable, fair play, "quid pro quo" types where they reward the person who flatters them the most. They are cruel, arrogant, and domineering. They will set up a competition for who will give them the most love and admiration, and they will take all that love and admiration from all sides, and then
they will do whatever the hell they want. You can flatter them, cajole them, praise them all you like, but if they can make a few bucks by screwing you over, you're screwed. Sometimes they'll squash you no matter what you do: they enjoy squashing people, because it makes them feel powerful. Someone in good repute, "I know them", "we've got a good relationship"; The same person when in trouble, "I don't know him": stop being useful to someone like Trump, you're dead to him - there's no loyalty and no friendship. You don't exist as a fully formed, independent person to Trump, he only views you as a tool to manipulate to get what he wants.
Secondly, people like Trump still have beliefs and values. Trump is macho arsehole authoritarian: he admires Putin and wants Putin to admire him in return. Putin will always count for more in his eyes than someone like Merkel. Trump clearly has a huge grudge against Obama: he's going to tear down Obama's accomplishments whether or not he's been flattered to do otherwise. I suspect he's at least mildly (if not substantially) racist, and he will favour white people over black. If you want to pass a bill that will personally cost Trump money, I doubt any amount of buttering him up will do. He's vindictive: if you've opposed him in the past, no matter how much you suck up to him, he's not going to trust you and will look for an opportunity to take you down.
This cute idea that Trump can just be filled with flattery and will duly pull out the goods is little more than a psychologically comforting fantasy. He's not nice and safely controllable, and it is not everyone else's fault that he wasn't prodded in the right direction. He's got his own beliefs, his own motivations, and carries out his own actions, and they're the main part of how we've ended up with this clusterfuck of a presidency.