The V710 has version 6 of Motorola's iTAP predictive text input. More information about iTAP can be found HERE.
To listen to MP3s in stereo, use the Motorola MS525 - SYN9870 one touch stereo headset. This was confirmed in an email from Motorola even though it's not listed on Motorola's V710 accessories page (as of the day I posted this). It can be found on Motorola's site HERE.