This is mostly opinion but to answer some:

Cover
It was completely broken. PLD had the possibility to take a double tank buster on its own and take 0 damage with Hallowed Ground.
Today it's not that strong and the effect is not worth the 50 gauge. Yes it needs something.

Oblation
Don't underestimate Oblation, its flexibility is incredibly useful in content with very high damage.

Orogeny
Yes, I agree...
Samurai has 3 of those, cooldown shared between a ST and a AoE variant.
In my opinion this is pure button bloating. In certain content it will never be used and just occupy your hotbar.

No mercy&Inner release
Timer based buff were a big problem which is why WAR got it on stacks rather than duration.
You needed a specific SKS to get all 5 GCDs within the timer and that SKS depended on your ping.

Same goes for No Mercy, if you extend it many will seek to fit one more GCDs in the buff window.