Safe travels Tom. I look forward to hearing of your adventures. Don't blame me if the car driving proves to be the wrong choice! Glad you're not driving straight from the airport, never a good idea. Forget the car around Valletta.
I have just remembered: eating in Valletta seemed very pricey compared to what we had paid elsewhere. We wandered three or four blocks away from the main shopping/tourist area into streets frequented by local business people. Had the most marvellous tuna salad, enough for two, for very few euros. Would have been four times the price in the Main Street, at least. The local 'sports clubs' in most villages also do reasonable local food at very good prices. You do not have to be members of the 'club' and get a good local atmosphere. You have clearly done your research but remember that tipping is only required if no service charge is added. Huge tips are not expected, 5-10%, or round up the bill to a sensible level is all that is genuinely required. We were made welcome everywhere.
Have a fabulous time.