Thanks, I never thought of those fish to be a threat since they are all very friendly, except the shark who just hides all of the time except for food which I hand feed anyways. But I'll take your word for it since your what I'd consider the Betta expert.
I don't really want to set up any more tanks for a few reasons. And for the 10 gallon, when the platy are gone, it goes into storage or just sits dormant until needed again. With of course the filter still going.