Since taxes are involuntary by definition, I don't think they can be just. Since they are involuntary, my preference is that they be as avoidable as possible: i.e. only on luxury/sin goods.

Tariffs on goods between private parties are certainly unjust, but when one or both parties are state actors (or other criminals) it becomes less clear.

I'd prefer the government not be funded and just go away. If I can't have my top choice, then I think funding it through fines and fees levied against legitimately criminal acts is the best way to fund it. Taxes and fines on antisocial behaviors, narrowly defined, would be the next best.

Edit: On the representation note, I'd also say people shouldn't have to pay taxes unless the person they vote for wins and they're in the ruling party.