TL;DR version: Drop the Dreadnaught. Use some of the points to optimize your Grey Hunter Squads. Spend ~170pts on a better value unit.
Unit By Unit breakdown of the list:
HQ:
Rune Priest 110pts
Chooser of the Slain
Living Lightning
Jaws of the World Wolf
Looks fine.
Elites:
Venerable Dreadnought 190pts
Plasma Cannon
Wolf Tooth necklace
Wolf tail talisman
Too many points for an armor 12 vehicle. He's nearly 1/5 of your total points, and brings very, very little to the table aside from a single plasma cannon (meh) and a mediocre showing in h2h. He lacks the volume of attacks to do much more than tarpit, and anything with good h2h will be able to kill him.
If you want shooting, this could be an entire squad of Long Fangs, or predators, with points left over.
If you want Close Combat, this could nearly be a squad of Thunderwolves.
Troops:
8 Grey Hunters 201pts
Power weapon
Melta
MoW
Wolf Standard
Wolfguard + Wolf Claw & Storm Bolter
Rhino 35pts
Not a big fan of Power Weapons. /shrug.
Also, on the Wolf Guard, no reason to take a storm bolter. 1 more bolter shot isn't worth paying for.
Take a Combi-Melta (extra melta shot is totally worth paying for)
You also might want to consider a Power Fist/Thunder Hammer instead of a Wolf Claw. You're not losing out on any attacks, and at I4, you're going simultaneously/after most real combat units anyway, wounding on 2s is nice. Being able to rip open Rear Armor 10 vehicles is nice. Etc.
5 Grey Hunters 126pts
Power Weapon
Meltagun
Wolfguard + Power weapon & Storm Bolter
Razorback 40pts
Pretty much ditto the above comments. Not a fan of PW. Not a fan of Storm Bolter.
In a small squad like this, you might want to just drop all close-combat upgrades (2x power weapons) and use the saved points to put a real gun on your razorback (LC + TL PG or Assault Cannon)
5 Grey Hunters 143pts
Power Fist
Meltagun
Wolfguard + Power weapon, Combi-Melta & Melta-bombs
Razorback 40pts
Wait, why do these guys have a power fist? As above. Smaller squads don't survive combat well, so you might as well just got Melta + Combi-Melta and upgrade the Razorback.
5 Long Fangs 115pts
4 Missile Launchers
Yes, the Space Wolf Staple...
I would suggest revising the list as follows:
HQ:
Rune Priest w/ Magical Bird (whatever powers suit your fancy. I like cover saves) 110
Elite:
Wolf Guard (in squads, points counted there)
Troops:
8x Grey Hunters (Banner, Meltagun, MotW) 248
Wolf Guard w/ Thunder Hammer, Combi-Melta
Rhino
5x Grey Hunters (Meltagun) 178
Wolf Guard w/ Combi Melta
Razorback with Lascannon + Twin-Linked Plasma guns
5x Grey Hunters (Meltagun) 178
Wolf Guard w/ Combi Melta
Razorback with Lascannon + Twin-Linked Plasma guns
Fast Attack:
Heavy Support:
5x Longfangs, 4x Missile Launchers 115
Either,
Shooty/Mech Option:
Predator w/ Heavy Bolter Sponsons 85
Predator w/ Heavy Bolter Sponsons 85
Or,
WAAAAGH/Close Combat option:
(Drop Large Grey Hunter squad's Wolf Guard ThunderHammer to a PowerFist) -5
3x Thunderwolves, 1x Power Fist 175
999pt List either way.
The predators add some extra Dakka and Armor 13-fronts that you can use to screen your lighter Razorbacks. With a Rune Priest nearby casting Cover-saves, your armor wall will be quite durable and, with the Missile Launchers, should be able to take out (most) light-mech armies you'll see at this point level. Though Grey Knight Henchmen spam could be problematic (6-8 Razorbacks T.T)
Alternatively, the Thunderwolves give you a "hammer" unit (well, for 1k points anyway, they're a little light) with a 24" Threat Range to help you control the field and digest any pesky units that might otherwise be too much for your Grey Hunters to handle.