Minus One questions

1) If no attack dice make range, can a defender still choose to roll defense dice in order to get rid of a Defense-1 token?

2) Can an attacker or defender choose to use more than one Attack-1 or Defense-1 tokens?

I'm not 100% sure on these, but I would say no for both of them.

Not sure on the first question but in the main rulebook it does stat only one -1 defense or attack tokens can only be used per roll.   It's at the bottom of page 4

Judging from the wording of the attack/defense resolution steps, I think that if their is no attack dice after range/misses, then their is no defense. But that's just an interpretation. 

Agree with Kimetsu, you need at least one die to roll against.  

1&2) No.

Thanks