Without knowing anything about the software side of it, it just sounds like you're running too rich, or to high of an idle. That 1200 RPM is about what the startup RPM is until the car is warm. Normally too once you put it into gear before warm, it does drop a little, maybe to 1000rpm, but still feels more tension on the brake is needed to keep it from going forward to hard. But again, once warm the car is going to idle around 700 RMP all day, in or out of gear.
Not really any solution, just sharing how my 2014 seems to run, and what I perceive as normal behavior vs what yours seems to be doing.