I'd synch the carbs and run a tank or two of fuel with carb cleaner (Redline off ebay) to see if that helps clear any partial blockage in the pilot jets and passageways.
If the carbs have never been off the bike, the float levels will be spot on from the factory. They always are.
I wouldn't discount plugs or plug leads if the problem persists.
Some Fazer 1000s do have a lumpy idle irrespective of what you do to perfect the carb synch and so on. Those are the Friday afternoon bikes.
On the other hand, there are those that are accidentally blueprinted on the production line and those run like sewing machines.
You can do the 'which pipe is the hottest/coldest' test if you wish but I suggest you use a spray bottle with water not your fingers. The results are same but without the sizzle coming from your flesh ...
My apologies to all who are waiting for me to come up dates for a visit to England this autumn. We're still touring Europe at present and we won't know what our calendar looks like later in the year until we get home at the end of June. I will be doing my very best to fit in a trip towards the end of August/early Sept, I promise.