"Are there any ways to earn Mithril in-game?
Mithril can only be purchased in the LOTRO Store for now."

Once this is in game, will it be Turbine's intention to make all 'low-ticket' items purchasable with Mithril Coins.

Ultimately will Turbine be replacing deed rewards of Turbine Points with Mithril Coins, effectively forcing the currently free system into a half free and half purchase system? Thus gating the 'high ticket' (also known as high selling) items towards people willing to pay cash?

This is the only reason I can think of for making some brand-new features 'streamlined' into a new currency.