leather and iron do not appear on the smithing perk tree.. what level do I need to be when I can improve my iron and leather gear beyond fine?

I don't think you can.

When you have enough smithing skill, you don't need perks for Leather or Iron.

yes you can and i think its 30 or 40 im wearing a pair now

is crafting iron daggers the quickest way to get smithing up?

http://www.uesp.net/wiki/Skyrim:Smithing

31 without any perks in Smithing or 22 with Steel perk, I may be wrong.