Depending on the age of the device and how much you use it, this is screen burn and very common across the Samsung range. If in warranty I would advise to take back to samsung to get replaced/fixed otherwise a new screen will fix the issue. Nothing to do with being “hacked” at all. Hope this helps.
This could be a possible Charge ic replacement where the current dead battery will not take or receive charge. If possible try to get a battery with about 40-50% charge on it already then test it. Or get a separate device to charge the new (old) battery to make sure it can accept any charge first
Depending on what wax it is, you can use a heat gun or hair drier and slowly heat the bottom of the phone where the speaker and mic is then use an old toothbrush with a little methylated spirits or isopropyl alcohol on it to clean. never try to push it in as this will most likely end with damaging the mic or speakers.
Unfortunately I’ve had this to me a few times after a battery replacement and 9/10 it always comes to the touch ic chip on the board. If you can replace yourself, cheap fix otherwise if you have to take to a repair shop they usually will tell you to upgrade as it isn’t worth the repair as it is a very common fault.
I have come across this problem once before at work with the 11 pro, unfortunately the device must be repaired through apple so that it is covered and returned fix otherwise you can replace the front facing camera with a third party one but will not have facial id anymore. the restarting of the phone is caused by the faulty camera.
You have unfortunately damaged the LCD within the phone. Thus causing the flickering or permanent black or green line. If you turn the phone off and look under extreme light you will notice a crack on the LCD. Best option for this is a replacement screen.
Unfortunately the LCD is damaged and will require a new one. These screens are very thin and easy to break and yes it does happen to everyone too. When letting it set I do recommend LCD clamps like the one in the photo bellow to get best results.
Given the age of these devices and depends what quality cords have been used over its life, I would recommend a new battery for this device but you do run the risk of damaging the screen so best thing to do is take it to a third party repairer to do it or if you are confident enough to do so.