A second concern:
We will be spending 5 days in Collioure (without a car).
Using public transportation, can you suggest possible daytrips
near the Collioure area? Thank you for your input.
Without a car this is probably impossible. But we loved Dali's house in Cadaques, Spain. Very interesting and worth the trouble.Also, in Collioure there are wonderful artisans shops. One thing to watch is the mistral wind...when we were there it was very very strong. My husband who is a professional photographer got a lot of sand in the sensor of his camera one day when he was photographing.There are lovely other surrounding areas , but , for me, I would want a car unless you were going there to sunbathe.
I believe there is bus service from Collouire to the town of Caret, which is inland and interesting in its own right.
Ceret might be manageable, despite Rome2Rio's estimate of 2 hours for a train+bus combination. Rome2Rio is highly unreliable on details like frquency, travel time and fares.
The larger city of Narbonne is easier to get to. Banyuls-sur-Mer is another little coastal town to the south of Collioure. I think it's not as interesting, but for a change of pace you can hop on a bus and head south.
Best of all, Collioure isn't far from Perpignan, which is the rail and bus hub for that part of France. If the connections are frequent enough, you may be able to take the Yellow Train into the Pyrenees. Regular SNCF trains run from Perpignan to Villefranche-de-Conflent, where the Yellow train begins its run. VdeC itself is an extremely picturesque fortified town. Yes, it is very touristy, but at least most of the tourists are French or Spanish.
All that said, I think 5 days is an extremely long time to be in Collioure without a car.
Edited to add: Be very careful about planning an out-of-town jaunt on a Sunday or holiday. Transportation schedules can vary a lot by day of the week, and bus service can be cut back sharply on mon-workdays.
Andrew, thank you for saying what needed to be said about Collioure. It is heaven, and the pace of life is slow and glorious. An hour or two on a bus or train, a hike into the beautiful hills around the town, or a half day spent just meandering through the town all refresh the soul. There are distractions to be had, if that is your pleasure, but somehow just "being there" is really enough.