If you sit down quietly and read the manual, look at the videos on the SD card, view the various videos from TiggerRC,Simon Newton etc you will be up to speed and find that just about all your concerns will be answered. Do remember the old saying "What goes up - must come down" in the case of motor/esc trouble the P4 it will be rapid and in the case of the H it will be controlled.
Redundancy is the feature word to describe an H not applicable on a P.
I did't that a few hundred times but that change the software
