Differential amplifier with feedback resistor
The analysis I made led me to believe it would provide positive
  feedback and thus won't stabilize the point, but I dont feel safe
  enough as to assure it


Your analysis is correct. If point A rises slightly, T2's collector drops slightly. When T2's collector drops slightly it turns on Q9 more and its drain rises in voltage and, if that drain (point B) is attached to point A it will raise point A a bit more and rapidly the circuit hits the rails due to positive feedback.