I think the solution to collecting the sales tax is simple.
Let the states collect it. Most already have the mechanism in place to do this.
Then, we move away from a national sales tax and let each state set the sales tax where they want.
The federal gov’t, limited by a balanced budget amendment, can only spend so much. That amount is divided by the number of citizens in the last census.
Each state is required to submit the amount to the federal gov’t based on the number of citizens in their state.
This will solve several issues:
1) It eliminates federal taxes completely.
2) It eliminates block grants and the federal “cut” taken by bureacracy before the money gets to the states.
3) It returns fiscal control to the states.
4) It takes away the incentive to count illegal immigrants as citizens. Counting them increases your tax bill.
5) It encourages states to stop being sanctuaries for illegals as more enforcement will be used to get them off programs that cost the states money.
6) Each state can be creative in their sales taxes and what is being taxed. Some might tax services, some might not. Each state can experiment with their taxes and tailor it to suit the types of industries they have in those states.
I like some of your ideas, but you are talking about largely dismantling the Federal structure. Good luck with that....