Basically, the idea is that if you get stunned or knocked down while channeling, it'll stop the spell? I guess there's room for allowing damage to break the channeling too.
Yes, thats exactly the idea, i didnt thought about DMG interrupt, but that could be too.
And yes, its a new mechanic that allow the game to be more tactical, since, as you said, linked fire could use on an alli, and then telep him, you also can charm someone with the link, and of course you can make a mess if the linked one use that link on his advantage.
Its just a new concept, that i thought it could be fun.