Your flight plan looks fine:
just a couple of notes:
DON'T LAND at Roma Urbe (LIRU): too many problems. Just avoid it and land at Perugia (LIRZ) which is just 60/70 miles north of Rome.
It looks quite a short trip from Pisa to Perugia so I'd suggest you to fly direct from Pisa to Salerno.
Don't land at Lamezia airport as there's no AVGAS available. I'd rather suggest you to fly direct from Salerno to Catania.
2 questions:
1) what is the estimated endurance of your pa-28?
2) what is your estimated endurance in flight?
Knowing, for example, that you're planning 2 or three hours long trips would help...
CIAO