On Downloaded Media and Social Interaction
So I opted to disregard this "offline" option in the app and use Freemake Video Downloader to download optimal quality versions of any video I want, making it possible to download the one at a time to prevent my connection from being too slow for other tasks I may be doing at the time. Then I use Microsoft's SyncToy to transfer all those videos to my device to have the real opportunity to watch them offline. But this prevents the possibility to like or disklike those videos while I am watching them.
A short term solution, but rather cumbersome one is to bookmark the source of those downloaded videos or create a special "like-dislike" list in youtube so you can go back later and like dislike them when you are online.
An ideal solution would be to implement a standard for any video player application to recognize the url where any video comes from through some sort of fingerprint or hashtag of the video and offer you the option to like or dislike, or even comment on the video offline and posting that actions to the right media source when connection is available. This way, you can even rename the downloaded video files, the option will just work the same.
The only thing that will breack the hashtag is transcoding, but hey, I noticed that when using the automatic "optimal" quality in Freemake Video Downloader to automatically choose witch quality version of the video to download it is not necessary (and rather counterproductuve) to use the option to transcode to Android version, if you do that you usually end up with a bigger file, that's nonsense. So in that scenario this ideal solution will hold operational.