I plug my information into Mr Malty along with the date on the pack and it tells me that I need 7 packs of yeast with a 2.8 liter starter.
If the pack were a month old, I'd only need one pack and a 2.5 liter starter.
Getting back to the OP, sure it can be done with one pack and stepping up...
Sure, you have to make a starter, but at what age do you become concerned about the date on the pack even though you should be able to use it?
I got a Wyeast pack from an online vendor that's almost 5 months old. The pack didn't swell and the starter took forever to get going. The time lag...
Not really. It's the same for everyone :D
For a 5 gallon batch:
.8 oz of 15%AA for 60 minutes contribute about 25 IBU
1.0 oz of 15%AA for 60 minutes contribute about 31 IBU
1.2 oz of 15%AA for 60 minutes contribute about 38 IBU
This is just for one ounce of bittering hops.
+/-.2 oz...