IPhone 4S cameras do not work after iOS 8 upgrade

Question

I have an iPhone 4S 16 GB, It worked perfectly under iOS 7.1.2. . . I upgraded the OS to iOS 8.0.2 about two weeks ago. ( Bad Move )
I noticed right off that my device was running a little slower, lagging, and worst of all my "Camera"  App does not have an image At All ! ! !
The Flash options, HDR options, Timer options, will switch back and forth, but that is all that works, none of the bottom selections work at all,
and when you hit the front/back camera icon, it freezes /locks the options that did work. I have done a deep restore twice on the device,
restored as New Device, still no change at all on the behavior of the Camera operation. One thing I did find out though, it is a Glitch in the iOS
software, pertaining to the Cameras Operation, reason being, is that I can go into the preinstalled Game Center App on the iOS 8, click on Add Photo,
click on Take Photo, and there are my cameras, working perfectly, front & back. I have done a lot of research on this issue over the past two weeks,
Reading Apple's own Compatibility Devices which start at iPhone 4S and later for the iOS 8.0.2, But, If you go into the iPhone iOS 8.0.2 Operators Manual, go to camera section, you will see that there are several of the New functions of the Camera that are only compatible with iPhone 5 and later. Leaving the iPhone 4S not capable of executing the full capabilities of the New Camera App. I've chatted with Apple Online Chat Support for several hours two days ago, the only resolve they had was to send the device in or take it to an Apple Store and they would correct that issue "Free of Charge", even though ,my iPhone is 3 years out of warranty, because it is a Software related issue.... All I wanted to do is find a way to revert back to iOS 7.1.2, I found out very quickly, that is Impossible to do, because it violates Security Issues and Apples Terms of Agreement," Leaving them Not Responsible for any issues what so ever that occurs to your device downloading the iOS 8.0.2. . Which in my opinion, is pretty messed up. . What is the Big Deal of reverting back to any iOS you want, Apple should support every iOS version they have, not the users fault that a New iOS does not work right on their device, slowing it down, etc...I run Windows 7 on my PC, I can revert back to any OS I want, no problem at all.. . Anyways, back to iPhone issues, The other issues I got with the upgrade is that, My device will not power back on after I power it off now, I have to do a reset to get it to booted back up and running, and when I do so, there is a white halo that appears on my screen for several hours, then it will finally dissipate (no idea what that's all about), , Also, the battery life is much shorter now, had much better battery time on iOS 7.1.2 . . . Apple Support said that my Case was the first they have heard of, which surprised me.
<Edited By Host>

Answer 1

I'm not quite clear on how your phone is working right now. I also don't know what "every possible thing" means so here is what you can do to troubleshoot software issues yourself. To be safe do a backup before doing anything.
Restart or reset your iPhone, iPad, or iPod touch - Apple Support
Use iTunes to restore your iOS device to factory settings - Apple Support
Get help with the camera on your iPhone, iPad, or iPod touch - Apple Support
Just so you are aware, now that you've had a local hardware person repair the phone you no longer have any warranty or service support from Apple. Good luck.