UrukGuy

This

The corsairs of umbar flee the boats, the party & rangers take the ships. The whole point of the fleet was to cut off the Dol Amroth reinforcements, which can then join the battle

At Pellenor, they just scare the enemy forces. Once they've fulfilled their oath, they are free.

Exactly, veterans with a stockpile would be able to just buy the lot

I'm not sure if it is a problem, each currency has a specific purpose (ie materials split by expansion for a more level playing field on expansion release, faction specific, event)

I feel like it's well designed if anything

The problem is when games go for size is that they don't populate the world

The modern Assassin Creed games were a prime example of this - big world, completely barren