Why is it debt-based?
Because it is financed using future profits, which allows the economy to develop faster, but on credit.
How does it create inflation?
This is a side effect that occurs due to the increase in the emission of money. The more pieces of paper circulate in the economy, the less valuable each individual piece of paper becomes.
How do banks, central banks and world governments manipulate all this?
There is such a thing as an inflation tax, which allows all of the above guys to make a profit from the money of their citizens.
Why was the gold standard better, and what could happen under a bitcoin standard?
Better in what?
For example, the gold standard is worse in terms of economic growth rates. That is why it was cancelled.
Bitcoin standard doesn't yet exist and it is not known whether it will exist at all.