All of those a good suggestions to get over a Khornate 'flavour'.
Personally, I wouldn't have a problem with you painting them how you wished. I think the berzerker models are distinct enough to be obvious... if I was playing a chaos army and my opponent plonked down a unit of bone-white or dark green berzerkers, I wouldn't think, "oh they can't be berzerkers, they're the wrong colour". I would assume they were berzerkers, and expect him to tell me if they weren't!
I run a Blood Angels list, but use Chaos models. As a result, I paint them pretty much as 'straight' Blood Angels. The tac squads are red, with red helmets; the dev squads are red, with purple (blue) helmets; the assault squads are red with bone (yellow) helmets; the Honour Guard will be red with brass (gold) helmets; the Death Company are all chainaxe-wielding berzerkers wearing black... Apart from the spikes, they pretty much look like a Blood Angels army.
In general, I find that it's best to help your opponent as much as possible with identification... if things aren't quite as they "should be" I think it's best to keep them as close as you can, so something like the red shoulder pads would be a good plan. Which might mean you need tips on painting red, sorry...
"Well it's Forty-one Thousand Nine Hundred Sixty-nine OK -
Gotta war across the Milky Way - "
Iggius Popiscus and the Stoogii, "41,969"