It's not an accounting trick it keeps budgets honest. Otherwise outsourcing would be at a huge disadvantage even if they also get that money back.
Also the 60:40 vote issue this is why we use a representative democracy backed up with a constitution. It's harder to stay in office when you regularly piss off large voting blocks. A politician will often consider more than just what percentage of the population would vote for something but how much people on both sides of a issue care about it.
Wait, what? There is a group of people outside government that produce something that did not exist yesterday. Through taxation people called "government" are taking part of that product. (I'm not saying if it's good or bad, it's just what it is.)
Then they use a lot of accounting here and there, but it does not change the fact that in the net some people had some property transferred from others to them in a non-market fashion (not in direct exchange for some other product, but because it's a "rule"). In my view it means that "taxation" is not applied equally to everyone. So it cannot be an example of a "fair" rule that you defined earlier.
Of course, we may talk whether redistribution of wealth is "good for society" or not, but that's outside the question of "universality of the fair rule".
Hmmm, well, yes, and I don't know why you don't see it yourself. The people on government payroll are doing something for their income (and they are taxed like anyone else, but to avoid routing money around it may be deducted before they get paid... Here in Spain it's not the case, they pay income tax like anyone else). Not everything is a product that is sold: education would be the simplest and more down-to-Earth example.
Also the 60:40 vote issue this is why we use a representative democracy backed up with a constitution. It's harder to stay in office when you regularly piss off large voting blocks. A politician will often consider more than just what percentage of the population would vote for something but how much people on both sides of a issue care about it.