Had kites I've had to tweak a bit but all with bridles and I think they set them up 'tame' from the factory so I've done things like; adjust rear lines to fly on shorter depower or lengthen them to unhook better etc.
Never had a kite wonky though and my kites for the last two years have all been Airush Razors that are perfect out the bag and the 11/9/7 all fly on the exact same bar.
For a C kite to be wonky must be shoddy build as I could understand bridles/lines being a little out and maybe the aggregation of small defects can add up to slight steering issues, but with a C?