[e_d_e_v]

I think IP ownership does = stewardship of all domains using that IP from a DV certificate perspective. The moral of the story is don't point a domain you value at a sketchy host's IP. The list of the things that need to happen to work around poorly managed hosting providers in this scenario is overblown. No one should host anything they think is important on shared hosting. Full stop. That is about as much of a reality as the above statements around SNI, but it is something individuals can actually act upon.