Hmm, I have 4 personal planets in air signs, plus an Uranus singelton and a air grand trine. My finger adn toes are not long nor am I tall. I know people keep saying Gems and Aquas are tall, but sorry, I don't see it. Sag and Cap, followed by Cancer have been - based on my experience and chart reseach - have been the most consistant indicators of height. Aquas seem to often give the "illusion" of height (did you know Paul Newman's only 5'9"? He seems a lot taller than that yes? LOl!), and Gems are typically pretty average in heights (Kylie Minogue, who's 5'2", and Prince, who's 5'4", arem't exactly statuesque, for example - neither are I, 5'5", or my mom, 5'4", and we're both Gems too). Libras seem to vary a lot.
Pisces - regularly associated with shortness, including in limbs and digits. Often hands and fingers, as well as rest of the body, are wide, even plump. As for Kurt Cobain, he did have a Cancer moon, but he was actually very short, 5'6". To the eyes of the public, he seemed "well-built" which was hardly the case! He was not only short, but had a curved spine that slumped his shoulders (bad posture is another Piscean trait) and was chronically underweight due to G.I. problems (Virgo rising). But despite that, you could still see the Piscean "widening" effect on his short frame - his face and shoulders had pretty good width for his height (added to his media attractiveness - had he been chubbier it would have been more obvious and he less photogenic). His hand and feet were fairly broad as well. Being a guitarist myself, I can tell for pictures of him playing guitar, his fingers may have look big on his tiny body, he had relatively thick fingers with stubby, rounded fingertips - classic Piscean, just like my fingers.
However, Cobain did have Pluto and Uranus conjunct his ASC: as I mentioned above about Aqua, Uranus on the ASC seems to cause disproportion in limbs too, which seemed as the case with Cobain. While I don't see his fingers being very slender or long relatively, his arms were definitely too long for his overall frame - very much like RHCP guitarist John Frusciante, who's a Pisces-Aqua. In Frusciante's case, he has more Aquaish traits, although likewise isn't very tall (probably no more than 5'9").