Artifact Armor 4 idea

[Ophannus]

It's going to suck really hard if we need to +1 our Relics with -1 gear from CoP Dynamis before we can augment it into +2.

I stopped reading here. If you relegate relic equipment +2 to synergy, you'll isolate the players. Those who have no interest in synergy won't bother, even for this, and those who are just starting synergy will have to grind for a few months just to get their skills high enough to finish their relic equipment +2.

Short answer: No it won't.
Long answer: Just like augments with sky/abjuration gear, someone else with high enough synergy can augment your gear for you barring they have high enough skill to do so. You don't need to have synergy skilled to augment your own gear, others can do so for you, probably for a profit(unless they like you).