Retirement tax questions

@dmertz 
Wow! Thank you for yet another very  helpful answer! ERSGA said they emailed something but if so, my husband probably mistook it for spam. I will have to ask them what portion was this year's RMD.  For the part that was from interest and is referred to as taxable, we rolled that into a traditional IRA because at that point I did not know that the contributions were after tax. In case your generosity continues, my remaining questiosn are these.

1) Will we be taxed on the part (outside of the RMD portion) that was from after-tax contributions?

2) If so, can we reduce the amount of tax we owe on the refunded non-RMD, after tax contributions by rolling that over to an IRA?

3) If so, is it best to use a Roth IRA since it is after-tax money?