at the east coast the hotels have some nice beaches without stones, shells or corals, just seen it in Palmar this weekend, but it might be a bit fresher there in our "winter". But I guess you are used to other winters.
I remember that Le Morne in the west had some nice beaches where I haven't had so much issue with above in the sand or water, and the water there is already quite deep close to the beach. But this is only some experience from about two years back. Haven't been there in a while now ...shame on me.
I am not so sure about restaurants on the east coast around the hotels, maybe in Flacq you have a greater choice or just ask at the other hotels if you can also eat there.
But normally as you wrote half board you can have enough during the day with a decent breakfast from the buffet and same at night with dinner. So maybe some fruit during the day might be sufficient.