The standards for wealth vary by the age and area. At a certain time and place, simply not having to work for your own food was being as rich as it gets.
Yes, but wealth as a general concept is somewhat different to taxes, which have a much more specific connotation
You shouldn't discredit the taxes of the masses, imo. After all, how did the nobles become rich? By taxing these very same masses. Per head, they contribute a lot less... but since they are so many more than the nobles, it kinda balances.
with regards to source and implementation.
