Hey there!
I play Mechanized orks.
I don't want to copy/paste the entire book I just put elsewhere....so please do me a favor, click this thread, and read the very long post I just made about thematic play with Orks.
http://www.dakkadakka.com/dakkaforum/posts/list/310129.page
Also in there is my own mechanized ork list, and links to some battle reports where I've taken the Pink Waaaugh! out and curb-stomped almost everyone.
At 1500 points, I'd give you a few pointers.
1. 9 Lootas is a bad choice. Take two units of 5. You get to fire at two different targets instead of one, and honestly....all you *need* is a shaken result on something with a lot of guns for it to be effective. 5 Lootas shaking a vendetta that in turn can't fire at your battlewagon with its triple twin-linked lascannons is a unit of 5 Lootas paying for themselves. Just as importantly, Lootas have a 48" range - the weapons that can range you are anti-tank weapons - meaning that your opponent has to choose between your tanks and your Lootas for targets. ALWAYS make them have to make difficult choices.
2. Nobs in 1500 is iffy. You *need* a powerful unit, but in 1500 points, you're forced to dedicate so much of your army point allocation to the unit to make it worthy of taking that you hurt the rest of your army. 1750+ is another story, but at 1500, I would leave the nobs out.
3. Trukks: Eh. An exploding truck probably means 3-5 dead boyz, leaving you with a potentially pinned and understrength scoring unit. In my mechanized lists, trukk units are simply there to back up my main efforts. Wherever I'm not sure I'm bringing enough force to decisively end a fight, I add in a trukk full of boyz to swing the fight in my favor. Honestly, given the amount of tanks out there, and how easy it is to explode a trukk - I'd shy away from them in this edition.
4. You *do* need a powerhouse unit. You have Ghazghkull, who can literally take on anything in
40k by himself (except for a C'Tan), but that's only good while he's on the Waaaugh! Have you considered burna boyz?
5. Gretchin!!! Don't underestimate the value of a 67 point scoring troop choice of 19 dudes that can hold the backfield objectives to free up the rest of your army to go kick tail.
I'd continue with a book, but let me just provide you with a 1500 point list and let you decide if I'm worth listening to for yourself.
HQ1: Ghazghkull Thraka
HQ2: Big Mek +
KFF
Troop1: 16 Boyz, Nob + Powerklaw + Bosspole
Troop2: 12 Boyz, Nob + Powerklaw + Bosspole // Trukk + Reinforced Ram + Boarding Plank
Troop3: 10x Gretchin + Runtherder
Elite1: 15x Burnas
Elite2: 5x Lootas
Elite3: 5x Lootas
FA1: Deffkopta +
TL Rokkits + Buzzsaw
FA2: Deffkopta +
TL Rokkits + Buzzsaw
FA3: Warbuggies x2 with Twin-linked rokkits
Heavy1: Battlewagon + Deffrolla + Big Shoota + Grabbin' Klaw + Boarding Plank + Armor Plates
Heavy2: Battlewagon + Deffrolla + Big Shoota + Grabbin' Klaw + Boarding Plank + Armor Plates
Total: 1498
Ghazghkull with Burnas in one battlewagon,
KFF with boyz in the other; if you lose either one, there is room for the
IC to jump into the other battlewagon and keep trukking. All vehicles have boarding planks for extra anti-vehicular ability. Whether the burnas are dropping 15 templates out of their wagon (and boy, if you read some of my batreps, you'll read some fantastic stories about causing 90+ wounds to units) or assaulting with all power weapons, you have your dead killy answer to death star units to back up Ghazghkull.
you saved me from eternal gameloss. luls. 
like your avatar too.