You are having a good analysis about these two different discuss yet related in nature especially as they are mostly related to online.
IMO, I think that trading is learned and more professional than gambling. It is believed that if you learn trading, you can do better than someone who did not learn it but just trades on the market. But gambling is strictly looked at as a lucky game. I remember in time ago when gambling has not become popular, it was usually referred to as lucky deep. That is the classification of gambling. it is believed to be unprofessional although the times are changing.