Okay so I am back with more information as I went through more tinkering.
I reinstalled EndeavourOS KDE (I had to as swap partition was not added). Then I also installed AKM for easier installation of the headers (and kernels).
I went for:
- sudo pacman -S nvidia-installer-dkms
- then i installed yay -S nvidia-470xx-dkms
- then, via octopi, I installed nvidia-settings
It also works with 470xx. It’s staying more at 52 Celsius degrees but, even so, it’s too much for an Nivida card to stay at this temperature with only a browser and 5-10 tabs opened. The fans are raving/amping less than it used to on 515 and 510 but it is still not okay.
Moreover, I can sense a very subtle water-motion like when watching videos (youtube via chromium while having Override software rendering list, GPU rasterization and hardware acceleration turned on). It looks like the video would not be 100% synced with the audio… but also the video being a little bit slow… 
So… the operating system has these codecs installed already sudo pacman -S a52dec faac faad2 flac jasper lame libdca libdv libmad libmpeg2 libtheora libvorbis libxv opus x264 xvidcore (no wavpack but I don’t think that would be a issue.)
After I also installed opencl-nvidia I tested again and it’s the same.
Now this seems to not be a Nvidia installation/uninstallation issue anymore but a proper configuration of it …
What do you think guys? How can I make this Nvidia GPU run smooth and not get so hot? 
