I think different regions will employ different models, but under a bitcoin standard, I don't see the need for tax but others may disagree.

The easiest would be consumption tax adding VAT on products and services which then filters down into the central treasury, others may consider a land tax, but only on size, how you develop the land should have no baring on how much you should pay. it's only on size and then its up to you to use that land how you feel.

Others may consider bond offerings to raise capital for certain projects but I think most things can be done privately. Example, If I have enough cash i'll build a road and charge people to use it

I don't think people realise how much money is wasted by the government and if they were removed how much value would circulate amoung people to build things themselves and provide for private services and charity