Your canon update is approved. However, our canon updates don't physically remove characters from Thedas, only give them new memories. We assume that the new abilities you list are abilities he always had or always had the capability to use but did not previously use, rather than abilities gained from some external source since his last canon point. If that's the case, they can be added, with the caveats below. If any of them are new abilities acquired from an external source/event/etc., however, he won't be able to use them.

↠ Transforming people into stone: fine for the same duration that mages are able to freeze targets solid in combat, will require focus/energy to maintain.
↠ Paintings coming alive and trapping people in paintings: not in Thedas.
↠ Statues: if he wants to make a statue of himself he can use it this way.
↠ Transposing into reflections: nnno. :C
↠ Vines: Fine, as long as they're in his line of sight and so on.
↠ Domino: with all the usual caveats - they must be in line of sight, etc. - this will work. It will be limited to three people at a time, and if they do leave his sight it won't continue to work in his absence.
↠ Doppelganger: he can cause hallucinations similar to this, but not duplicates capable of physically influencing the world.
↠ Mesmerize: he won't be able to summon a spirit.