thank you for your interest in FLING.
Let me try to address your questions.

1. When i mentioned "nº", i was talking about dice results - low numbers (nº) like 1 and 2 are usually a failure, while high numbers (5 and 6) tend to be a success. You could fill the Competence table the other way around, since what matters is the amount of symbols you allocate, but i figure that's less intuitive. 
Example: competence table (filled on character creation) for [eye actions] (sensory, discerning, aware) >> if you are really good on these kind of tasks, you could end up with these numbers (nº): 1=failure, 2=partial success, 3,4,5,6 = success. But if you filled the table differently, you can end up with a character like this: 1,2,3=failure; 4,5=partial success; 6=success.
 
2. Fling was created for a 1 page RPG - i couldn't spend much lines setting proper examples. Like you stated, this is subjective. But, let's try to come up with something for [sensory actions]... so, finding a needle on a haystack: consider this one the "Unreasonable" task; see if someone is lying to you is "Average"; and spot the girl among the men it's "Insignificant". But for instance, if the person lying is an actor, i say it's "difficult", but if it's a son or a husband, trying to do the same trick, i imagine it's easier for the person who knows their tells, so it's "easy".

Does it makes sense? Hope I've helped. Let me know if you still have some questions. English is not my main language, so I apologize in advance for some confusion.