Question 1. The length measurement appears to be inaccurate.

Yes, that could be but keep in mind several factors that can affect this.

For example, during one of my many tests I used a Yo-zuri Mag Darter as a point of reference.  The plug is listed as 6.5".  I added that as a new reference in the app and when I calculated the length of a Bluefish, the measurement had come in a couple of inches of what I had manually measured using an actual ruler.  After a closer look the plug, not including any hardware, the length came to approximately 6.30".  I remeasured it using the updated length of the reference object and the measurement was now exactly the same as I got using a ruler.