Why can the government use force to do things ordinary citizens cant?

You could but there are more of them than you. Just pay your taxes and stop thinking too much.

Your question is vague. All I can say in response is the govt can do anything that (1) Is specifically spelled out in the Constitution, (2) Does not infringe ion the peoples' Constitutional rights.

Because the government is only as powerful as it's civilian force allows it to be.

Or at least it should be.

Why have a government if they have no power to keep order?

Because people put them there to do it knowing otherwise that we'd be living in a chaotic mess.

Because they have to follow less orders

Yes, taxes are a good example.

i believe it's called "tyranny"