I think it would be less, but I also think there would be less need of charity, as the standard of living would rise across the board without the government sapping so much productivity out of the economy.

Would the standard of living really rise for the poor though? I don't really know. Is it not possible that people, and corporations, could find ways to funnel the wealth generated from these new sources of productivity into their own pockets instead of distributing it?

Probably the same thing we did before the New Deal instituted all these government social welfare programs.

Why would we have implemented social security programs in the first place if what we were doing before was working? Maybe not all implemented programs have been effective, but something was clearly wrong with the current system at that time.

if the government charged for services rendered, as any other business does, then I think most likely fewer people would subscribe to the government's services, as they could find higher-quality, lower-priced alternatives elsewhere.

The service the government provides is the allocation of pooled resources for creating things like infrastructure and legislation over a given area. By optional tax, I simply mean giving each individual the choice to contribute to the pool (which would, in my opinion, not be a good idea). The difference between the government providing this service, and any other business, is that we at least have some say over how the resources are distributed. A corporation, that always has profit in mind, would not adequately do this job.

Yes, I do, with a proviso: this only works if we eliminate corporate limitations on personal liability

I'm sorry, I don't fully understand limited liability, but why would it prevent corporations from being untrustworthy. Is it just because those participating/funding the corporations would not be protected by it?