I think merit points could work well, if they're done intelligently. It can't give a high enough bonus that it would become a mandatory grind, but it can't be too low that it's not even worth implementing.
This is going to sound silly, but how about a Merits Vendor where you can trade in Merits for the following items, assuming it be split amongst DoW/DoM, DoH, and DoL. Like, "Militia Merits", "Artisan Merits", and "Forager Merits".
Militia Merits could buy the following, in order of price:
Aetheryte Tickets
Spiritbond Potions
Durability Potions
NQ Draconian Potions of <Insert Attribute Here>
NQ Combat Food Items
Silver Chocobo Feathers
<Armor Type> of the Pious <Class Name> (Steel Vigil Glamours, Dyable)
<Armor Type> of the Outcast <Class Name> (Sohm Al Glamours, Dyable)
<Armor Type> of the Orthodox <Class Name> (The Aery Glamours, Dyable)
<Armor Type> of the Heretical <Class Name> (The Vault Glamours, Dyable)
<Armor Type> of the Sagacious <Class Name> (The Great Gubal Library Glamours, Dyable)
<Armor Type> of the Vengeful <Class Name> (Valerian Glamours from Fractal Continuum and Neverreap, Dyable)
<Weapon Type> of the Just <Class Name> (Stone Vigil Weapon Glamours)
<Weapon Type> of the Feral <Class Name> (Sohm Al Weapon Glamours)
<Weapon Type> of the Ancient <Class Name> (The Great Gubal Library Weapon Glamours)
Dusk Leather
Artisan Merits could buy the following, in order of price:
Aetheryte Tickets
Spiritbond Potions
Durability Potions
NQ Tinker's Calm
NQ Crafting Food Items
Replica <Crafting Class> <Armor Type> (Crafting AF1 Glamours, All Classes, Dyable)
Master <Crafting Skill> I
Master <Crafting Skill> II
Rowena's Token (Red Crafting Scrip)
Dusk Leather
Forager Merits could buy the following, in order of price:
Aetheryte Tickets
Spiritbond Potions
Durability Potions
Hi-Cordial
NQ Gathering Food Items
Replica <Gathering Class> <Armor Type> (Gathering AF1 Glamours, All Classes, Dyable)
Matron's Favor <Insert Area Here>
Trader's Favor <Insert Area Here>
Rowena's Token (Red Gathering Scrip)
Dusk Leather
Footnote: For those who don't know what Dusk Leather is, it's used to make the Company glamour set. However, at present, no one knows where to get the stuff.