From the screenshots you've provided, I don't see anything too terribly wrong with your device. You're still getting a full day of use, and your screen on time is great. That said, there are a number of issues I see that can be corrected to help your situation. There are a few things from your screenshots that I can't understand because they are in a different language, but from what I CAN see, you're over taxing your device with a ton of apps that consume a lot of processing power. WhatsApp, CNN, Facebook, Facebook messenger, Google Maps, and various games just to name a few. Couple that with various widgets and your device is going to get much warmer than normal with all of this going on. That said, I don't see anything that needs to be "fixed" by Samsung. My advice to you would be start from scratch & do a factory reset. After which you'll want to only download apps you use on a regular basis. And again, don't run your battery down so low. Plug it in throughout the day, or at least once it hits 15-20 percent. From time to time you'll want to open up your recents (left capacitive key) and hit "close all" after you've run a number of these power hungry apps.
As for the slippery issue...
nothing on your device, whether it was an update or being rooted is going to physically cause your device to be "slippery". Most phones these days are slippery when a case isn't being used. Personally I think that a combination of sweaty hands and no case, (or a smooth case) would cause this. My advice would be try a different case to see if that helps, perhaps something more rubberized. I've had an Incipio Dualpro case on my S5 for almost 21/2 years. It's was nice and easy to grip in the beginning, but over time it's become very worn down and can get slippery if I'm not holding onto it tightly.
Good luck!
S5 tap'n
Thanks for your suggestions but sadly I already did those things you mentioned.
Normally I give the system a few days after flashing a new stock rom or factory reset before I install any apps on it to make sure apps don't cause the problem. I couldn't remember the exact numbers but there were many apps installed on the phone before performing the firmware update. I remember the system did optimize over 100 apps due to update after reboot.
I even try to boot the phone in safe mode (all third party apps disabled) but it is same.
Yes I know the battery thing from my notebook and the smartphones share the same thing so I am very careful about it. Even after four years my notebook's battery only has %6 wear level which is perfect. I never let the notebook or the phone completely dries out.
Screen on time could be confusing because most of the time I did use the phone at lowest brightness in those screen shots. Usually I don't get that high numbers. Idle is not good like it used to as well.
If the problem occurred from the first day I bought I would agree with you. But the phone was completely non-slippery for me for about six months of usage. It was only lukewarm even at maximum load. Many people I know use their S5 without a case because of its non-slippery design. Even Samsung states why they choose the dot design for the S5 over the S4. For better gripping.
Please take a look at these screenshots:
The first two are from a video I captured by Mobizen app a year ago (24.09.2015). I did buy the phone a year and a week ago so this is the first week. Notice the battery temp. It was charging through USB cable and I was trying to record a movie by recording app Mobizen. So the system is heavily loaded. It was at 34.3 celsius at that time.
The third one is taken recently, three days ago (22.09.2016). 7 months after performing the firmware update. I was only taking screenshots of the phone to post here. The battery temp is at 39 celsius.
I'm posting idle and screen on time screenshots as well before and after the problem occurred.
Before (almost four days idle time, still predicts 7 hours left AND over four hours screen on time):
After (one day idle time and three and half hours screen on time):
You could clearly see something in the phone really ****** up. And nobody could fix it. This is what really bothers me most. I have never seen anything like it. What a mess...