1) Telenav as a service is either part of your Sprint Vision data package or it is not. The software is part of the 3.35 firmware, and therefore is "free" from that point of view.
2) As for the Sprint software, many of the customizations are not needed. You can avoid them by doing a hard reset and skipping the customizations during Windows Mobile setup (just hit the reset button when the prompt appears with a 3 second countdown).
Alternatively, you can use
nueExtROM to unlock the Extended ROM and delete/replace the contents for future hard resets.
That said, you need to keep the
Sprint_IOTA.cab tool.
Hope this helps.