I disagree with all of the above.
I routinely use a Warboss with big choppa, kombi-skorcha, eavy armour, cybork and squig. He's cheap and very efficient. I don't fancy striking last against those pesky power weapons/fists, this way I get to make use of his good initiative on the charge to do some chopping. I leave power klaws to the Nobz that can't be picked out and beaten up on. That said, I mostly play against GEQ armies where I don't need to ignore armour saves that badly. I'm not saying a power klaw is ineffective, just that a big choppa can be effective as well.
3 Nob Bikers ought to be fine at this points level. They're a durable unit even when not in large numbers thanks to multiple wounds and their built-in cover save. I wouldn't mind seeing a Painboy riding with them for Feel No Pain irritation, but I don't think this is a bad unit by any stretch.
I think that, much like the Warboss, equipment on a Trukk is simply a matter of choice. Grot Riggers are handy buggers to have around, since they keep our Boyz on the move, and the wreckin' ball is cheaper than a plank. They're also more reliable against tanks that have moved more than 6", as they always hit on a 4+. Armour plates are certainly handy though.
Warbikers are definitely a good option. You pay for two good saves, mobility and (relatively) reliable, hard-hitting shooting. They're a fast, durable unit that can hit quite hard and stay in the fight for a while. I don't think there are any bad options in our Codex, simply ones that need to be used properly.
While I don't disagree that the killkannon should be gone, I do disagree that it's meaningless. Against a unit of Marines, it works just fine. It doesn't cause instant death, true, but it doesn't need to against most targets and S7 will still wound most things on a 2+. There are things in the game besides Nobz that need killing. A burna won't kill a Nob, does that make it a bad weapon? Of course not, because not everything has a Nob statline. The killkannon has a place, it just isn't on a transport 'wagon.
I don't mean this to sound like an attack on you, please don't take it that way, but from what I've seen of your posting on other people's lists, you have a habit of finding fault with everything. I think it's better to try and make the army he wants work rather than chuck everything out and have him playing your list.