the government does generally not pay its bills by issuing dollars. Instead it issues bonds, which private investors, institutions and nations buy.
Nope. The government has a list of primary purchasers (In Europe it's banks, I assume it's the same in the US). These banks are the only people who cna buy the bonds. The others you mentioned only buy them on the secondary market. Now sure, generally the primary buyers intend to sell to the secondary market. But they don't need it to turn a profit on the bonds. Every purchase of US bonds can be made with brand new US dollars provided by the Fed. The banks don't need to be liquid or have secondary buyers lined up. They just become the middle man between the Fed creating new money and the US government spending it.
If you issue more dollars, you are inherently reducing the value of dollars already in circulation.
Nope. This is monetarism, it's a neoliberal brainworm and has been thoroughly debunked. You are straight up spreading misinformation :( There are so many more factors at play such as, is there full employment, are people saving or spending (or does the money go to people who spend more or save more), are there sufficient resources available to accomodate the spending, etc. As a rule, unless we're at full employment, government spending only causes inflation in very specific cases, not in general.
Also I can't stress this enough but most money is created by banks when they loan to the private sector, not by the government.