Is there any way to use conditional statements in default value formulas in
infopath? I know rules can be used, but they only fire when the value of the
field changes. I have a large set of columns ( turning Excel into InfoPath )
with some pretty complex dependencies [ on values in other columns ] and I
don't want to put 100 rules on each column, but would like to get away with
setting default values.

This question spawns out of my laziness and additionally since my
understanding is having a ton of rules on each field is a bigger performance
hit than setting a default value.