Rome this fall with elderly father

When my wife and I took my 78-year-old father to Rome, we had to think hard about mobility. He has some issues getting around, so we ended up investing in private tours for the big sites. It was worth every penny. We went with Walks of Italy and made sure to ask for their accessibility specialist. They handled Vatican and Forum/Colosseum tours for us. For food near the Vatican, we stumbled on L'Isola della Pizza over on Via degli Scipioni. They easily fit our big group and served up fantastic, truly Roman dishes—none of that overpriced tourist stuff.

I'd recommend Santa Margherita Ligure over the Amalfi Coast for your situation. We found it so much easier for my father, who has mobility issues. The seafront promenade stays mostly flat, with lots of benches scattered along the way. The town itself has gentler terrain than Amalfi's notorious stairs and steep inclines. Santa Margherita gives you that gorgeous coastal vibe, but without the crushing crowds. You can also hop on short boat trips to Portofino and other charming spots. No need for tons of walking, which was a relief.

we have two days after Rome for a side trip.

Is that two nights or 3 nights to give you two full days at your 'other' location?

Presumably you have to depart/fly from Rome for your trip home?

How many nights total do you have?

Amalfi coast towns cling to the cliff side. You are almost always going up or down.

Florence is definitely more friendly for the mobility challenged than the Amalfi coast area.

For the mobility challenged, seeing the Amalfi Coast from the water would be a great creation of memories, I'd think.