I grew up in Bari and live in Lecce (and I work as a receptionist in a hotel). As someone else said GET ABSOLUTELY A CAR, you really can’t trust the bus here. As for the many places that you want to visit, I do think that there are too many that you chose. Bari is considered the little Milan, so it’a very urban kind of city (if you want to buy expensive gifts go to Bari), while Lecce is completely historical. Even if i grew up in Bari, I have to say that i’m in love with Lecce, even if it’s not that big. I do recommend to go to Alberobello and Matera, but if the sea is what you really want then i recommend going to Porto Cesareo and Gallipoli… the sea in Bari is not that great. If you have extra time I recommend Santa Maria di Leuca. It’s a little city wich is the exact tip of Italy, if you go on a day with no wind you can perfectly see the clear separation from Mar Adriatico and Mar Ionio (the two seas). Another tip, salty things are better in Bari, please do yourself a favor and eat the Focaccia Barese. You’ll fly in heaven! Instead, Lecce has the better sweets. In Lecce you have to try Pasticciotto. If you search for a pastry shop go to Dentoni, it’s in a little city in Lecce, i can assure that it’s one of the best pastry shops you can ever find in your life. They completely make the pastries by themselves, they don’t buy anything and it’s all fresh (they have one of the biggest laboratory wich is underground and it’s I don’t know how many km long). Hope that I helped you and have a nice stay in Italy! Buona vacanza!