Question Looking to start making a Vita dock, need electronics advice.

Apr 21, 2019
Note before starting, I have very little knowledge of electronics, good knowledge of 3D modeling, and limited programming experience. I'm looking to design and 3D print a dock for the PS Vita that has a Raspberry Pi 3 B+ to output video. This has been done before, but I want to also add a battery pack that will allow the Vita to charge while not outputting video signal and serve as a play stand for on the go gaming with a PS4 controller.
What I think I would need and want to know if it's possible/plausible:
• Make it so the Pi only turns on when it detects video output
• Charging bank with either a of the market phone charging bank with 1.5 A output, or a 18650-battery setup like you guys do in portables
• A switch that switches power output from Vita to Pi based on whether the Pi is on or not
• A way to split the USB cable from the Vita to the power bank/Pi
• Would be nice to also have a battery indicator​

Any advice and solutions as to how I can achieve this is much appreciated. If I get enough info to proceed I will turn this into a sort of work log.