Yes. You can never arrive at an absolute truth . There is always the possibility that undiscovered evidence is still out there to disprove a theory.
I ain't talking "absolute truth" here. Just plain old everyday homo sapiens "science".
Belief based on what?
Remember the Feynman quote? 
Thats exactly the point.
What's the point? 
What are you basing your beliefs on?
Absence of sufficient "deductive" evidence and proof. Seems pretty rational and reasonable to me. 
If there is no evidence to support your beliefs, on what rational basis are you believing in them?
How much evidence does a skeptic require?