I suggest you to check the blast furnace Wiki.
It is basicly the same principle as normal smithing in the furnace, but you only need 1/2 coal at blast furnace.
I have no idea what low cpu mode does, but ya there is some heavy logic behind some things.
A lot of things can't be checked in the client, so they ahve to be saved somehow
Ya sure, granted you 24 hours.
Khaleesi