title_body: Connecting 4 in 1 esc with power module
upvoted_answer: I think yes, this is doable. In this diagram you can replace the ESC Motor 1 with your 4 in 1 iflight ESC. Note that you will probably need to redirect the PWM outputs to your 4 in 1 ESC signal inputs.
  
  
  Could I provide power to the motors by wiring all of the positive outputs together of the power module
  
  No, no need to do that. Use a single power output of the power board (it is simpler and in certain cases more reliable).
  EDIT
  Following the discussion in comments, your 4 in 1 ESC already acts as a power distribution board. Depending on your situation, you may not need the power module at all. For example, one could split battery power output into two: one to go directly to 4 in 1 ESC, and another one to an UBEC to get 5V (to power the flight controller).