Will the Durametric system allow me to turn on the onboard computer so I can get the temperature display on the dash, as well as other functions hidden in the 2001?
No. You need the PST2 or PIWIS diagnostic tools for that.
Durametric will also not clear alarm codes- but they are working on that.
I've cleared check engine lights, airbag faults and ABS faults with it. Saved me a ton of money. They are also quick to respond to any questions you email to them.