Other retailers do it now. Again, it will be a burden if the states go after the little guy, but the big stores won't be hurt by it. The software is available at reasonable cost. I'm not sure how it works in other states or even in PA today (it has been over 35 years since I collected taxes) but for the 5% collected, I kept 1% for my fee and remitted 4% to the state. On a few million $$$ in sales, that 1% would cover some software costs.
As for writing checks, it is usually done by bank transfer today.