You need to learn more... we are in far more danger of having both an income tax and sales tax NOW than we would be if we passed hr2525...even without repealing the 16th first.
If we passed hr2525:
the IRS is defunded
all existing income tax records are destroyed
the income tax code is 100% erased from existence
all withholding ends - ALL withholding ends.
Now it is certainly possible to refund the IRS, research and recollect all necessary data on every individual, rewrite an income tax code and pass it, and convince the voters that we need to start paycheck withholding again. But that ain't likely.
Compare that to today- we have absolutely NO protection against getting both systems. We could wake up tomorrow with them.
If your concern is having two tax systems, you will want to pass HR2525 pronto, and not wait to repeal. That may take longer than our window of opportunity- cuz the dems don't like this idea ya know.