Ne, ĉi tiu frazo nur diras, ke tiu onklino ne estas stranga, kaj neniel implicas, ke stranguloj ne povas esti afablaj.
in this case it would be "my aunt is nice and not strange" right now it's like "my aunt is nice and that's why she is not strange". next phrases work same way as this one.
Ohh, yea, in those sentences it's more obvious. I think there are several ways to interpret this sentence, as in the other sentence you quoted it is obvious that ‘being tall’ and ‘being short’ are mutually exclusive. This isn't necessarily implied by the sentence itself, but rather by the properties used.
Hmm, I see your point, but it's not quite so clear in this sentence, hence I don't quite agree.
next phrases in this exercise. has same construction. like " he is tall, not short"
Here's a question - which language does afabla come from? Maybe "affectionate" (English) + "aimable" (French for kind/loving)?
English has the word affable, which comes from the Latin affābilis. So I presume that afable comes from Latin.
Nedankinde! Fakte, mi ne konis la anglan vorton; mi trovis tion en Wiktionary ;).