@lucian I'm sorry but option 3 is quite terrible. The problem is that, as a social network, people need to be able and encouraged to interact with each other on the actual network.
One of the main ways people interact with each other online is through sharing video and audio.
By far the major video and audio hosts, which almost everyone will need to use at some point, are ad based.
By sending people away to another site to view or listen you would be dramatically decreasing the likelihood they will comment or engage in the post here on Ello.
It will be especially egregious as embedding of YouTube and Soundcloud is dead simple everywhere else, and these services are major backbones of video and music creatives.
By relegating them to 3rd class status here you would be making a statement that this place is not for video artists or musicians. That it will not welcome their talent into the community as it has graphic designers and photographers.
This is just a step way over the top. I love the ad free layout, but it's not much of a social space if it is so rigid that the web's video and audio backbones are unwelcome noise.
If 1, 2 and 3 are our only choices, I vote 2.
But in reality, I would prefer 4: just allow people to embed whatever they want, and leave it up to users reading to decide not to play the media if they don't want to risk seeing a dread third party embedded ad.