Hi Yes the shops on bridge are very expensive, generally all shops are owned by same owners , so it’s difficult to get decent prices. Also you got to remember it’s very touristy so they going to charge you as much as they getaway with

Not that i know

Te recomiendo que camines, el trayecto es bonito y no te tomara mas de 20 minutos

Frescobaldi bar none. Look at the reviews

Siempre hay paso, pero en las mańanas es cuando hay menos gente.

I’m not too sure of they are real but given the tourist levels in the area I would be cautious.

Just today we took the train from Florence to Pisa and back. Trip takes just about one hour each way. Cost 8.4 E. Very easy, anyone can do it if we did! Trains run about every 30-60 minutes. We enjoyed walking around Pisa for 5 hours. Easy to get away from the crowds. We followed the old city wall.

Cars are not allowed

Ponte Vecchio is connected to adjacent street so has no steps, yes it's wheelchair accessible. However like other old town in Italy public toilet, not to mention disable toilet, are difficult to find. The only hope is the surrounding restaurant or shops.