Family holiday in Ireland in September. Any advice for ASD-friendly tourist outings?

My teen son and I are both autistic. We (with my wife and non-ASD son) are visiting from America for 12 days in September. We're hoping visiting during a non-peak time will ease some of the social anxieties, as well as focusing more on outdoor activities. However, we still want to enjoy things like some traditional Irish music and pubs. Can anyone offer advice or recommendations... either for things to see, or even places to definitely avoid?

Are ear-protectors allowed in places?

Also, we both have a limited food palate ("picky eaters"). Are food and restaurant choices forgiving of customizations? We visited London in 2019, and the servers were not very friendly about us asking for changes. The last half of the trip, we stopped asking, and my ever-patient wife would help with re-arranging our food.

Thanks for any advice!