Love to travel,
I am somewhat of a fast traveler, but not necessarily wanting to do that going forward. The biggest hindrance is my wife still wants to keep vacations in the three-week range. If it were up to me, I'd make them two months and slow down, spend more nights at each stop, along the way. If I can lay out a series of stops, I may be able to talk her into a longer trip.
My technique for deciding how long to stay at a particular destination is to first peruse the sights in the area, decide which are must-see sights for me, then plan enough time to see two bigger sights per day (and add quick stops like a fountain, or view, along the way). Some places are weeklong stays for many, but only a couple nights for me AND vice versa (much longer for me than the typical traveler).
I love history, notably 15th century or earlier. I probably won't be too interested in towns that were rebuilt in baroque style following their decimation from volcano eruptions or earthquakes. I'm hugely interested in anything from Carthaginian to Norman history in the area.
You have given me another thought, including Malta and Tunis as part of the trip. So much to see, such a limited life.