Well if I actually had the car to look at, I am pretty certain I could tell you exactly what the problem is. Since it is in the hands of another mechanic, its hard to predict what he is doing or seeing. Something is not right, and with the trans off it should be a no brainer figuring it out.

Also, don't compare the DSM to the 350, every car is different and so are the clutch mechanisms. Ideally you should get your DSM to shift right at the top of the throw just like your 350.

No, it is not normal for a DSM to shift near the floor. All my DSM's shift right at the top of the throw, where it is supposed to be.

Engagement point getting higher as the disk wears out is not DSM specific. As the disk wears out the pressure plate fingers tend to stick out more towards the throwout bearing. This in turn causes it to need lesser and lesser clutch pedal travel as the disk is released early (since the PP fingers are more towards the throwout bearing).

You may or may not notice this minute amount as you just get used to it over time.