I don't think there's an answer to either question in the quick-start rules, but I'll give it a try nonetheless.
sinisterthings wrote:The weapons table on page 9 of the SIF Fastplay rules lists the damage for Fist as Athletics - 3. I did not see anywhere a statement to the effect that "minimum damage is 1." Is the minimum damage 1?
I don't see why it should be. If a character with an average Athletics score of 2 should roll a total of 3 or less, he probably deals no damage on that attack (due to the -3 modifier).
sinisterthings wrote:How do Bonus dice in Athletic affect damage, if at all? I assume someone like The Mountain might have Athletics 4, 4B Strength. How is damage calculated in this case?
Based on what I've seen so far, I can see two answers to this question:
1) Bonus dice don't affect damage at all; or
2) it works like a passive test (see p. 5). So in the example above, Gregor would add +4 to his damage.
I'd lean towards answer 1, but for a definite ruling we'll have to wait for one of the developers to drop by and answer your questions. Or wait 'til October... (sigh)