So im a white knight should i be maxing combat orders?

Take into account Combat Orders does not last as long as other skills do. You don't want to be in the middle of a fight and suddenly you forget about CO and your skills take a dive in power, time rate, and other things. You won't be able to sacrifice 2 points in all non-required skills too. Remember you do have to use 61 points in first job, 121 in second, and 151 in third which won't leave too much -2 on full mastery, if any. Don't rely on CO as a crutch either.

When Combat Orders expires, only your passive skills immediately change. Active enchantments (Booster, Charges) are only worse if you re-cast them without first casting Combat Orders again. In order to keep your skills as good as possible, all you have to do is recast CO before it expires, just like any other skill.
Following a CO-reliant build, there are enough extra points left over after second and third job that you can fully max things like Mastery anyway.