I agree. The problems with your point about taxing the workers start at the asymptotes:
150 million workers have relatively little income compared to the top 1% who obtain a very large share of the income. They also have a lot more "tax events" and derive them not from wages but from capital gains.
We currently have 150 million workers and a middle class. Unemployment is going to have to be embraced when one janitor can clean 100,000 sqft building using a few very efficient machines, or a dozen workers can run a car manufacturing facility that produces a new vehicle every 3 seconds. At this level of productivity, which we are going to approach, the form of capitalism that assumes that those unemployed are a fringe group of people between jobs is not going to work. A new system is going to need to be developed, unless population is going to decrease at the same rate as productivity increases.
So the solutions as I see them are:
1. Make the government more productive so the tax wouldn't have to be quite so high. The government uses money in two ways: to run its internal services and to re-distribute the money. The former should be streamlined (making the IRS simple would be along those lines), while the latter can be reigned in by cutting spending to less needed services (e.g.: excessive military spending, tax loop holes, etc.)
2. Make the sales tax progressive by the type of item being sold. This goes hand in hand with your third point and can get complex, but the states already do this: food, clothing, and everything else are all taxed differently. Let's have a 50% tax on tobacco, and a 0.1% tax on food. Note that this is still more efficient than reviewing every single person's return and looking for exceptions.
3. Since the tax is national, there will be less problems than with the state tax in terms of determining where you have presence. Just charge the tax and that's it.
4. Issuing a refund at the end of the year does a person no good if throughout the year they cannot afford to buy food and shelter. To fix this, we need a minimum wage that actually lets someone support themselves. The amount should be re-evaluated yearly or if inflation jumps more than a regular percentage, and should rise with at least inflation. As we approach the productivity asymptote, basic income is going to need to be implemented as well.