I agree it's a bit quick 3 days in both Siciliy and Malta. Lot's to do and see in Sicily. However does one have to see everything? Really depends. We spent 1 week in Taormina but it was the summer and we like to go to the beach. We were never bored.

If you want to really see the island then I agree you do need 1 week minimum. But Taormina is the nicest part of the island.

Other parts to see are Palermo about 4 hours by car from Taormina, then Erice, Trapani and the temples in the south. Forget the name. Then Syracuse. There is also another town which is very beautiful. The stairs are made with tiles. Very famous but I forgot the name.

I think from the eastern part of Sicily to the west coast it takes about 6 hours by car. The roads are good; highways.

From the north to the south I think it's about 3 hours by car. You can travel by train in parts and also busses.

We spent 10 days in Malta and Gozo. We were never bored but it was summer.