is there any way that any type of brake booster issue can cause soft brakes?

 

Overboost would cause sensitive brakes, not necessarily soft brakes. If your pedal is spongy and the brakes don't seem to clamp very hard it's likely air in the lines. Any recent brake work been done?

 

yea, but no matter what I can't get them nice and hard. it seems if i do nice long drives without stopping they get softer, and I need to pump them to make them work good.

 

A failed booster will cause a dense pedal or hard pedal feel. If the pedal goes down with normal pressure just feels soft you probably just need a thorough bleed. So did you do brake work recently? If so what all did you do? Check out the link below for a how to bleed write up.

http://www.powerstop.com/how-to