Upon receiving the Roth Ira during retirement, will I have to pay additional taxes on my money received? If not, could this possibly happen in the future? What part is taxed and when?

The current rule is that as long as you meet the age requirement, distributions from a Roth will not incur federal taxes. Each state can set their own rules on tax treatment, so you can't readily generalize on state income taxes.

Will these rules change? The Roth rules will probably change many times... even before one year past we had a technical corrections bill. I would hope that existing Roth accounts would be grandfathered if the basic tax free status were to change. The more taxpayers (voters) that are affected by a change, the bigger problem Congress faces if they reneg.