A couple more discrepancies I'm noting before we get into it:
1) Your points are off in a number of places. Make sure you're actually buying the guns that go on the tanks and guys--there are no free weapons anymore. Ratlings, for instance, buy their sniper rifles these days.
2) The Platoon Commander, Special Weapon Squad, and Command Squad are all Elites choices now. It shouldn't affect your formation at all, but it's one of those little changes that throws people.
3) The Tank Squadron in heavy support: does the second Leman Russ have a hull gun? It has to, so you're either taking 3x Heavy bolters or 1x Lascannon/2x Heavy Bolters. It isn't clear which.
4) The Demolisher (that is what you mean by LRDEM, right?) mounts heavy flamers, not flamers (which might account for the points being off).
Now, as for the actual utility of the list:
1) There is really no reason to take a Lord Commissar as opposed to a regular commissar. There is also no reason to take a Platoon Commander as opposed to a Company Commander (assuming you have the HQ slots). I would swap the two. It will save you 10 points overall and be totally worth it.
2) As mentioned, the Vanquisher is a pretty terrible tank for the points. You're spending too much and getting too little. I'd switch this out for something like a Punisher, Standard Russ, or Executioner (though that last might explode). As a general rule, the Leman Russ is paying a lot of points to be hard to kill, but it is going to have a hard time earning its points back in terms of offense. The ones that perform best on that scale, in my estimation, are the Standard Russ, the Punisher, and the Executioner.
3) Autocannons and Grenade Launchers are pretty solid. If you can scare up an extra 15 points, making those autocannons into Missile Launchers might be the better buy, as those things are generally better at both anti-infantry and anti-tank than the AC is. Then again, the AC is better at killing middleweights (bikes, killa kans, Crisis Suits, etc.), so it might have some utility here depending on your metagame.
4) I'm torn on Hellhounds. The random number of shots is awful, but the auto-hits are nice. What I can't decide is if the cost of the tank overall justifies the offensive output. If you wind up testing this, let us know how it does.
5) Love Scout Sentinels and these look good.
6) The Demolisher is not an especially good buy for the points. The main gun is lackluster except against very specific targets (middleweights again) and for that reason not really worth the premium you pay over the other variants. Triple heavy flamers can go on any LR, so I'd pick the one that has the best main gun. The Punisher is particularly good for this role.
7) Haven't tried them yet, but Wyverns look great.