The problem isn't that Bitcoin will not be accepted. The problem has to do with regulation of the people and businesses who use Bitcoin.
Suppose that you want to pay your employees in Bitcoin. Okay, do it. But the IRS will want a full value reckoning, even if it doesn't include Bitcoin addresses. This means that the employees will have to pay taxes, the employer will have to withhold, and of course there is Social Security.
It will take awhile to get around the regulation of the people, not the Bitcoin regulation.
Study Karl Lentz. Youtube search "Karl Lentz common law" and take the time to learn.
No. Why do you think that way?
Employees should be paid as they are paid in past.
Bank to bank can be good for Bitcoin transfers. It's instant and it can be calculated instant too. Fast and secured. Why not?
But, even you (him/they) pay employees with (in) Bitcoin, there should be tax-free, as people have to get a full amount payoff.
Social security may be a problem, but dev's should working on it already.