If you're going from more traditional Western Astrological associations..
Sun - Fire - though when it is in a sign, it represents where exactly one's focus in life is likely to be
Moon - Moon (funny that!) Water - bearing in mind that he moon represents the more obvious emotions, and also intuition, money, and also precipitates events in general (in horary astrology). If you bring in Tarot connections, you could even pick up Illusion.
Mercury - Air, Motion, Communication - maybe Trade, could even see Man in there (it rules thought and communications in all it's forms)
Venus - Fertility - almost no doubt about that at all! Though Harmony does come into it (hey - it rules Libra... harmony through indecision

)
Earth... in Geocentric astrology, you wouldn't have it in the chart. In Heliocentric, you would - but then you wouldn't have the sun...!
Mars - Closest I can see might be Disorder (but might get away with Motion) - it rules the more fiery of our passions (including the baser ones of sexuality and brutality - thus possibly even Beast- but it's pushing it). You could even make a case for Motion - as Mars is the planet that is the impetus for moving...
Jupiter - Infinity (Jupiter rules expansion) and Luck. But also Truth.
Saturn - Law and Stasis. Saturn rules over the idea of responsibility, as well as heritage and tradition.
Uranus - Well... I can see Chaos fitting in here - where there is Uranus there is change. But Man rune also - as Uranus rules the realms of society (not the individual) - so when the wind of change blows through Uranus - all of mankind changes. Magic might fit a bit as well...
Neptune - Illusion (Neptune likes people to be self-deluded... but also gives us our dreams and hopes in life). Neptune is also a little Cold, and a little like the Shadows of our lives.
Pluto - Death and Spirit. Pluto rules over the hidden things, secret etc, as well as magic and its ilk. And there is no better planet for Death - the whole Underworld thing and all...
While it is true that 'the ancients' did see only the 5 outer planets (up to Saturn), there have been other cultures that managed to ascertain more beyond them. Also, depending on how you choose to interpret the idea of Atlantis, there's no real reason you couldn't have them knowing about all of them - after all, isn't that what magic is about??
And the 4 elements is purely a Greek thing - the Celts didn't bother with them (though they obviously used fire and water... but preferred things in either circles or triads), the Egyptians seemed not to have cared, nor the Assyrians. And the Romans didn't seem to get much into them either, for that matter -which is kinda odd given the connections between (proto)-Greece and Rome.
Just my thoughts (yep - I did a professional Astrology course many years ago...)
Slyt