I don't have the audiophile files but can answer #2

If you have created RB songs that used the non-audiophile RTs, you'd have to regenerate those RT tracks to get the advantage of the audiophile tracks. Once a RT is generated in RB, it is there until you change it. Same goes for any rendered songs done in BIAB.

Much discussion has occurred about whether one can hear the difference. In my music collection, my CDs have been ripped in a lossless format (FLAC) where the original quality of the Cd is not lost. If I convert those to MP3 or WMA (160 kbps), and do a side by side listen, I'd probably have to listen through headphones to have a chance of correctly identifying which is which. I'm sure the RT will be the same. If I was going to make CDs and I could afford them, I'd get the audiophile RTs. For live performances, I don't think it matters.

R