I think that the essence of you text is that the OP should use the correct timing tools for the 30V 2.8....and loosen cam gears you have to loosen gears.
You will need an appropriate puller to get the sprockets loose, but the cam bolts can remain threaded on, so the sprocket and puller don't fall off as it releases. The 2.8 V6 has a very long timing belt, so timing marks as used on the 1.8T would be unlikely to give identical timing to both banks in relation to the crank. Some other V6 engines use timing marks, but generally those are 60 degree-bank engines, with much shorter belts.
As to using the engine timing as-is: if you are content with how it runs, there is probably no harm in that.