12 Motor Calibration

i recently purchased a “pixhawk cube” and there are still a few questions after setting it up with 12*Antigravity 4006 from t-motor with 16" blades, paralleling the top one with the bottom one coax, i mean the top motor cable and the bottom one are working at the same time, and if the top blade is CCW then bottom one will be CW. now pixhawk shows dedoca automatically

1- is it the best option to go like this? i mean top one and bottom one circling an opposite direction?
2- not all those motors start at the same time, is it ok that they don’t start at the same time? (after giving it more throttle they will all start turning)
3- what is the best solution of tuning motors and PWM? i saw a few videos on youtube with the auto tune option but non of my newly downloaded softwares such as “Mission Planner” or “QGroundControl” does have that !!!

so far i couldn’t make it to fly, if anyone interested this is my motor layout:

QGC has auto ESC caliberation under ‘Power’ tab.