doesnt it go back to the times of the crusades when malta was a hub for trade and a main base for the crusaders
Malta goes back well before then

Its first inhabitants came over from Sicily prob around 5000BC. Some of the oldest buildings in the world are found on Malta - various prehistoric temples going back to around 4000BC, including the unique, underground Hypogeum.
Don't think Malta had anything to do with the Crusades, but it was responsible for holding back the Ottoman Empire's designs on Europe. If you're into history, read up the Great Siege of 1565 for a truly epic "siege". Also Malta was key to holding back Hitler's North African conquests during WWII. And suffered terribly for that.
Shame you missed the old buses, they were great.
Definitely. The new fares are over-priced and they've "re-organised" a lot of the routes. There's a few oldie buses still running around though - some drivers I think have gone back to them!
If you want to rent a car, which is worth considering, just remember, the Maltese drive in the shade

Definitely have a look at Mdina - the old capital - aka the Silent City. Depending on your budget, there's a very swish restaurant there at the Xsara palace, with tables up on the bastions. If it's too pricey at least go to the Floriana cafe on the bastions.
My mother's from Malta - second home to me! Parents married there too (in Mdina Cathedral). Oh, and if you're into churches, there's about 400 on the island; St John's Co-cathedral in Valletta is definitely the one to see (it also has Caravaggio's Beheading of John the Baptist).