If you want to split hairs about usage. Occasionally actually means you use/go/do on occasions. While sometimes means, some times. (not particularly related to specific occasions). Also I believe, sometimes is a little more frequent than occasionally. But yes, in casual speech I would say they are synonyms.
Whether the meaning of иногда is the same, I will leave to the native Russian speakers. I am curious myself.
You can say he goes to that cafe. You can say goes or comes to this cafe. I would orefer comes uf I was saying it inside the cafe. If i was outside, either would work. Russian word for "comes" is прийти оr приходить and auute a few ones with precise meanings which at this point neither of us need to know!!!