Alright, let us work from top to bottom.
First part of the list looks good. It is when we get to the bottom that we have some things that do not fit.
HQs- Big Mek- 'eavy armor is okay, but I would take Cybork as that is almost always a save while 'eavy armor can be circumvented pretty easily. I would give it a powerklaw or templater, but let us see where else we need to kut.
Warboss- Attack Squig adds a bit more attack here, making him that much more effective. Nothing else needed.
Troops- Trukk boyz are fine. Make sure they are slugga boyz at that too. As for the trukk, red paint job is almost mandatory. Stickbomm chucka I would kut to give trukk a rbj.
'ard Boyz are also good too, and if possible, give them shootas. Not required, but it does help.
Nobz- Okay. Nobs need to be unique in each squad. That means each nob must carry different gear. Give a few of them powerklaws, a bosspole, and if possible throw on them a few combi-rokkits or combi-scorchas and to make each of them different, add in a few ammo runts.
The battlewagon they are in is fine with most of the upgrades. Deffrollas are good, but if you cannot afford them/get them, then the ram is a distant second. Remove bomm chucka as well.
Add in a minimal squad of grots. Keep them in reserve and when they become available, have them sit on your objective. That allows you to attack all out against the opponent.
Fast attack: Deffkoptas: Make sure each of the Deffkoptas are by themselves, and give them a buzzsaw. They are your tank/transport hunters and they will suicide for you anything that is mechanized.
Heavy Support: DeffDread, Killa Kans and Looted Wagon should be kut entirely. Make the Looted Wagon a counts as Battlewagon and throw in some Burnas for the cost the Deff Dread and Killa Kans gives you back.
Now if you removed the Looted Wagon entirely, you could field another group of kans. In fact, if you were to remove the Deff Dread as well, you could field moar kans. And giving all the kans rokkits also makes them more versatile against other things like
MCs and armor.
Overall about half of your list is fine, and the other half needs fine tuning. You got all the requirements down for fielding proppa boyz squads. It is the nitpicking that straightens out a list a makes it bettah.
Other people will chime in too, but this is my two teeth.