It looks like the only thing the dragon marks do for me is hate gen when using the Epic Chimera's fang. The elemental protects are nice but I rarely use them, same with the globe of protection.
I find I do not use epic Chimera's fang much as I have better bastard swords. So I might be better off swapping those 3 dragon mark feats for other things.
Just have to decide what to use them on. Tactical feats? Other Dragon Marks?