Retirement tax questions

Thank you so much for your quick and thorough response! A couple of quick piggyback questions if you don't mind. Does me holding $ in a trad ira affect my wife's tax free conversion if we're filing jointly? Second question: Wouldn't it benefit me to convert $5500 of my existing rollover IRA in future years rather than putting in an additional $5500 of our money to convert? Taxes would be higher on it now of course, but when the balance is reduced in the future, a Roth conversion would have no other IRAs to be a part of. Correct? Thanks for letting me take up your time!