What taxes, if any, are included within a pro forma?

A pro-forma would usually include all the taxes that are payable by the vendor on behalf of the buyer. These are usually state sales taxes, or in some countries, may appear as a value-added tax (VAT) or goods & services tax (GST) applied as a percent markup of the transaction. The taxes included in a pro-forma should be those that apply to the transaction being taxed.

Is it a good? A service? A commodity, a major asset? Are there other fees & charges levied by local government that do not attract sales taxes?

The answer is:
It depends on what you are taxing, and in whose jurisdiction you are levying the tax and what rules apply to the calculation of the tax. Familiarise yourself with your applicable tax legislation.