The keyboard & trackpad share the same cable connect to the logic board. There are two possiblities: The battery is pressing on the cable as it’s failing and the cable it’s self got damaged from a bang on the bottom cover. I would check the battery using CoconutBattery to see how many cycles it has (if you’re over 700 it’s time for a new battery). Here’s the cable 821-00184-A trackpad cable for 13" A1502 2015 Retina Macbook Pro
The camera was not designed to be powered directly (doesn’t have a USB port). If you lost the charging cradle and power cord you can find them online. Here’s one - https://www.amazon.com/Canon-PowerShot-SX510-Charger-Replacement/dp/B00GWWPS0C
Your WiFi board uses a PCI Express Mini Card interface. So it’s conceivable a a short mSATA board would physically fit. The only risk is if the system would recognize it. mSATA SSD (mSATA solid-state drive)
The headphone jack has a switch element within it it looks like that’s broken or messed up some how. Did you plug in a headphone which was an odd length or size? It could have damaged it. Luckily Apple changed the design so you can replace the jack! It’s just not that easy. You’ll need to take the logic board out to get behind it to remove the jack assembly.