This could be due to a rip in the flex cable of the home button. In order to keep touch ID you would need someone to microsolder jumpers on the home button to repair otherwise you will only have home button function on certain devices. If the device is 7 and above you would need a special home button to keep the home button function.
So these are not that bad to repair. Will have to remove the back. Once you do remove the screws on the Charge port board and stick a thin metal piece under the board and use hot air to remove and place a new one on.
So normally when clips are added they tend to act as a ground for multiple parts. I know what clips you are asking about and they can be easily removed. If I remember right there is a total of 2 of them and they both take 2 screws. If you look at them they have a screw that is right under the lip that the screen lays against. This could be why you were having issues removing them.
1. Does not sounds like you need a new motherboard unless the port is soldered directly on your phone. If the port is soldered directly on then you can always de-solder and re-solder. If you don't feel that you are able to do this I would recommend taking it to a local repair shop.
Try the following: 1. Perform a software update on your OS if that does not work then it sounds like your Back camera needs replaced. Pretty easy fix depending on the type of phone. Normally is just a small camera that plugs into a FPC
Some possible issues and fixes for you. 1. Do a software update, this is found under General settings normally. 2. Update YouTube app and Netflix. Try a different app that would normally always have perfect sound.,Example: Pandora 3. The speakers may be going out on your phone. This would require the back glass to be removed and the speakers replaced. If I am right this will either be next to your Charge port on a flex.