I like most of this and believe you're onto something with the portal stones/Finn/Ogier and how Rand must proceed. I think the connections to all worlds other than the world in which they reside must be broken before the Pattern can be Healed (and think that, once that is done, Rand needs to break the seals, to clear the "last bit" of rubble so the Pattern can use the ta'veren effects of Rand, Mat, and Perrin to Heal itself). The only thing I would add to what you have said is that access to Tel'aran'rhiod is a part of that "rubble". For the sake of the Pattern's stability, I don't think anyone should be able to willfully touch any world outside of his or her own world.

Personally, I think it should go one of two ways: either Rand realizes what must be done and finds the key to stopping people from willfully accessing TAR (I think that people will also stop "accidentally" dreaming themselves into TAR once the Pattern is Healed) or once the weakness in the Pattern is healed, Tel'aran'rhiod will no longer be accessible to anyone. Since the World of Dreams touches every world, it stands to reason that it was the weakness in the Pattern that allowed people to access it. I also think the Talent of Dreaming should disappear along with the Pattern being Healed. Why? That's simple (and I will preface this by saying it's all my opinion so I don't get accused of stating fact when I don't put that statement before each sentence!)...

Dreamers are somehow granted the Talent to "see" other worlds when they dream. Call it soul traveling, if you will, but they are able to glimpse into various possibilities when they are in a dream sleep. Unlike foretelling, where what the foreteller sees is set in stone and will definitely happen, a dreamer sees possibilities - things that may or may not happen. In essence, they are seeing what is happening in one of the portal stone worlds. The closer the world that they're glimpsing is to the world in which they live, the more likely the dream will actually occur. But even the dreams Egwene has dismissed as unimportant likely show us some hint as to things that are happening in the parallel worlds. Some worlds are just more likely than others. The dreams that dreamers recognize as "true" dreams come from the worlds that are closest to the one they are in...and the chances of those occurring are quite high. So, should Rand really have to do something to ensure that contact between worlds be destroyed, then dreamers will no longer receive glimpses into other worlds and the Talent will disappear. That leaves Dreamwalking...

Natural Dreamwalkers (I've always been of the opinion that Dreamwalking can be learned and once you have learned what is needed, you can access it without a ter'angreal, but it simply is not taught anymore) are not only able to enter and leave TAR at will but can also access the "space between" to spy on other people's dreams. Since TAR touches all worlds at once, if the only way to keep the Pattern stable is to ensure no one can touch other worlds, then access to TAR must be removed as well (that goes double for the "space between", in my opinion). It's possible that it was the first Dreamwalker, or the person who discovered Dreamwalking, who causes a breach in the Pattern to begin with (which somehow spawned the idea of portal stones and ter'angreal that take you outside of the Pattern like the rings at the WT!). Perhaps the person was attempting to find other worlds or perhaps she did so by accident, but I'd be willing to bet that forcing one's way into TAR was the first tiny little hole that eventually let to the Pattern weakening and gave Lanfear the ability to sense that there was another power to be had. I think that it was the weakening of the Pattern that allowed people who weren't even dreamwalkers to dream themselves into TAR.

So, if the Pattern is Healed - and Rand does what you said and manages to close off all access to other worlds - not only will that mean cutting off access to Finnland, the portal stone worlds, and the Ogier's real world, it should mean cutting off access to TAR as well. And the talent of Dreaming will disappear. That, I think, would make a great deal of sense.