I have to say that you do yourself no favours by presenting a number of detailed points in an unbroken wall of text with no paragraph breaks, thus making them difficult to read and assimilate. If you wish to be heard, you need to think of your audience. Nevertheless, I shall try to address your concerns.
It seems to me that there are two main issues, namely: forum policy on downloading from YouTube videos, and whether or not it was appropriate for you to receive an infraction point.
Forum policy on downloading YouTube
I remind you of the forum Code of Conduct to which you agreed when you created your forum account. In particular:
The YouTube sticky to which you refer to is merely a clarification and amplification of the main Code of Conduct as it applies to YouTube. I also remind you of part of the last paragraph of the sticky:
We do not support circumventing TOS, EULA, etc here. Such threads will be closed and offending users will be penalised with infractions and warnings.
To pick up some of your points:
We are not a court of law. If you wish to challenge their terms hire a lawyer and take your argument up with YouTube. The arguments are inappropriate here as we do not administer their website.
Frankly, I find that a specious argument, but if it worries you, as above, take it up with YouTube. The terms of YouTube's ToS are clear, and we have to respect that.
It is additionally interesting that, under section 5.L of their TOS, they specify that videos are not to be downloaded 'permanently or temporarily', yet, in fact, ALL YouTube videos are 'temporarily' downloaded to any computer that accesses them.
It does not. I guess you are referring to a command-line app that is in the Universe repository. The Universe repository is not officially supported by Ubuntu, and you should not assume that anything in Universe (or Multiverse) is approved by Ubuntu.
Ubuntu itself provides a program for downloading content from YouTube.
Are you implying that two wrongs make a right, that because some uploaded material might infringe copyright, it is therefore acceptable for others to download it? If that is what you mean, I find that an extraordinary suggestion. And your second sentence is incorrect. YouTube have a clear copyright policy and a mechanism whereby copyright holders can request removal of uploaded material that infringes copyright.
Frankly, it is questionable whether the majority of the uploaders (Licensors) 'own' or have any rights to the videos that they have uploaded. It is presumed that most music mixes, videos taken from TV broadcasts, etc., do not have that right. Yet, YouTube allows these uploads.
Whether or not it was appropriate for you to receive an infraction point.
First to pick up a couple of your points:
A forum moderator dealt with your thread, not an administrator.
An administrator came on to the thread, closed it, and issued an 'infraction' to me.
You have posted in the correct place, where one or more of the seven forum administrators (who together make up the Forum Council) can respond to your concerns.
As the link you have provided does not allow me to forward my response to whatever administrators handle such matters, may I ask that you be good enough to forward same to the proper recipient.
Had you focused on the appropriateness of the infraction, I would have been prepared to consider that, and sympathetically. Instead, you tried to justify yourself with a number of unconvincing (to me) arguments about YouTube's ToS and the forum Code of Conduct. Before we go any further, I have to ask you: are you prepared to follow the forum Code of Conduct?