Up to 10 years at 1 daily update. Around 3.5 - 7 years generally with other configurations and applications

It is most likely that the device simply failed its first fix attempt (it will attempt one on start up) - if it fails, it will go back to sleep until the next scheduled upload. On default settings, this means not for 12 hours, unless you move over 250m from your position (to start a trip). So to attempt another, move to a location with good GPS reception, remove the batteries for 30 secs, and reinsert. This does not do anything special, but it reboots the device and will mean it will start up and attempt another fix and upload

Run hours can be tracked quite accurately using Jostle mode.

Odo readings are not as simple. Generally hard-wired devices should be used to track odometer readings. Getting an accurate reading relies on getting positions frequently enough during movement. The default 2 min logging can sometimes be OK, but it will never be as accurate as a hard wired device which will keep the GPS on during movement, getting a location more frequently and following every corner. The IQ-BAT will clip corners, or you can imagine in the extreme case, if you make a round trip between two GPS fixes and return to your start point, the distanced travelled will be 0m according to the IQ-BAT.

The IQ-BAT is not fitted with a coulomb counter, thus the battery life remaining estimate must be made on voltage alone.