Finally here Holoybro order !!

Hey all, Just got my brand new Holoybro Pixhawk4 … Love it ! Love it!
I do have a smsall question though and not really a question per se but more clarification LMAO!!
I have just gone throught the box and have mocked up the PM-07 with the PX4 and I was wondering if I have to solder my ESC signal wires to the PM07 pads marked M1-M4 or are they also off one of the pin headers even thought the pin headers are clearly marked FMU and CAP/ADC I can assume I need to solder my signal leads to the pads to make sure they come off the Main I/O header Correct ???
Secondly I notice there are 2 power input from PM-07 to PX4 but only one battery plug in .Why is this ?? I’m sure I missed something stupid simple on that one !!
Also where I plan to mount the PM-07 will be so super hard to get to after all is built, can I go ahead and plug in the power 2 cable the FMU and CAP/ADC cable and such while there is access ? Is there any reason to not plug these in and I was thinking of heatshrinking the unused ends and then making labels for them with my Rhino ???
Just some random thoughts anyways
LOVE the products everyone thank you so much for all the hard work into things like this