In traffic court, you are guilty until proven innocent. They don’t follow the Constitution.
That only applies to criminal cases. In civil cases, the burden of proof is a preponderance of the evidence. This applies to all civil cases. For example, if I sue you for damages, I don’t have to prove beyond a reasonable doubt that you did it — I only need to prove that it’s more likely that you are responsible. The burden of proof is higher for criminal cases because there you have the potential to lose your liberty (or life). That does not exist in civil cases.
It is possible that federal income tax violates it too. Search the web for more info on that.
No, it’s not. Income taxes are authorized by the 16th Amendment to the Constitution and the Supreme Court (who are the final arbiters of what the Constitution says) have consistently shot down all the silly tax-protester arguments.
The Wolf