I took my precautions. I noted that one of the motor plugs (when the battery was off) seemed not perfectly inserted. Besides I was very cautious during the operations.
I also was thinking that the phantom I have has an uneven weight distribution. Not only the weight is distributed to the back due to the battery but to one side due to the gimbal shape.
This means that one of the motors is teorically more under stress than the others because it need to maintain leveled.
I believe there is still a long way to go to engineer a perfect quadcopter. I don't understand why they did not creat some small opening at the top. The air flowing under the propellers would help to cool the esc's.
Excuse me, but you don't know what precautions to take if you know nothing about electronics.
If its not broken, don't fix it.
I've been opening electronic components for 35 years. And there ALWAYS place for screw ups even if you know what you are doing.
Also, on device like a phantom, a lot of vibrations happen during operations. You will never have the sturdiness it had from factory with all screws fastened with the same torque, and the 2 half shells united right after molded.
you will now be more prone to loose connectors and screws.
"I noted that one of the motor plugs" - you obviously don't have know how to identify such a problem.
In your car, if you open the engine lid and you "noticed that one of the pistons seams a little off" will you disassemble your cars engine, and post photos on the internet for someone to diagnose?
"I believe there is still a long way to go to engineer a perfect quadcopter. I don't understand why they did not creat some small opening at the top. The air flowing under the propellers would help to cool the esc's" - again: you seam not to have no knowledge of cooling and air flow. you don't just pluck holes on it and think it cools faster. That is why on a computer case you don't remove the case when it overheats. Air flow needs tight pathways to increase airflow speed and cool more efficiently. But again: how is that, a reason to open your Phantom?
"This means that one of the motors is teorically more under stress than the others because it need to maintain leveled. " Again.. is this your expert opinion, or the opinion of someone who opened an expensive piece of equipment to peek inside with no electronic knowledge? and if you were right in your assumption, what do you want to do about it?
Chances are, you are now gonna screw up something putting it together, your bird will crash and you'll blame it on DJI. Its not a wish. its a bit probability. take it from someone who has made that mistake on lots of electronics before. You'll learn with your mistakes. It will just be some very expensive mistakes if you learn it with your Phantom.