Unstable YouTube playback

Hi,
The YouTube addon is unreliable and requires repetitive work to setup and use. First, when trying to connect to my YouTube account, I had to go out of Kodi, browse to youtube.com/activate and enter a code from Kodi there. I had to do this twice, for no obvious reason. Then playback worked for some time, then started to fail with an error message about exceeded daily limit, with a super annoying sound. I tried using a custom API key, it was a real pain to get set up because copy/paste from browser to Kodi is not working. I ended up tweaking the XML configuration file of the addon to add the API key. It worked for a couple of days, then the addon reset itself to a stock API key which started to fail again. Each change of API key requires to reconnect, and the addon never gets the first activation code right (or I am not quick enough to type it), so I have to enter two codes for it to reconnect.
YouTube playback works from Firefox so this is not an Internet connection issue. But Firefox doesn’t make use of hardware acceleration as Kodi does, so I hear the CPU fan spinning all the times, and I like Kodi’s ability to navigate through YouTube using just the keyboard.
Any idea why this addon is failing so miserably and any way to improve over this, without having to go to a standalone box like a smart TV or Bluray player with YouTube support?