:3 feels good to be right.
You get access to a shop around Chapter 4, I think. If you think Lunatic is bad, after you beat Lunatic, you unlock Lunatic+ which is even worse. The difficulty in Fire Emblem games is not about demonstrating your awesome tactical prowess. To win you basically have to turtle, turtle, turtle. Ultra-defensive, with the abuse of every mechanic available. I honestly suggest restarting on normal difficulty. Permadeath is enough of a challenge already.
Yeah, Dice. The DLC map is quite good for the free EXP. You can do it as many times as you want, and the two towns on the free map will give you random items ranging from crap to awesome.