Which parameters should I track with bicycle computer so I can analyze changes in my riding?
You will obviously be able to get this from your trackpoints, but it can be useful (depending on the frequency of collection of trackpoints) to take speed - directly from your front wheel tacho if possible. This just gives you a higher degree of accuracy.

Other nice to haves:

accelerometer input - both fore-and-aft, and left-and-right - these can give a good correlation between the movement of the bike and the cadence and gear readings so understand how the power is being transmitted to the road.