tedi k wardhana

hi all,
I am not into touring yet, but have been bike commuting for over two years now.
since touring involves bringing lots of stuff, does the weight of the bike alone concern you?
how light must it be?
or
how heavy is the upper limit?

also other questions:
-must it be made of steel? (for strenght) or can be aluminum??
-how low gearing must your bike have? is 28 front, 28 in the back with 700x35 tyres be enough (for hills?)

thanks....