I'm assuming Mount Bane is a volcano. Volcanos tend to be named based on what they do and how destructive they are, or occasionally based on mythology or something in the local area. Since names evolve to describe the thing they're talking about, one would expect the locals to have traditionally revered it. To begin with, many would refer to it as "The fire mountain" or some variant of that. I'll assume the volcano is a hotspot, so it'll be highly destructive in nature. If nothing culturally relevant happened there and if the locals never revered it, then it would likely be named whatever the local word for "Fire mountain" was, which you could make up easily enough by looking at what "fire mountain" is in the language of the places closest to the island's location. For example, if it was near to Japan, I'd expect it to be named something similar to Akayama (red mountain).
As for Oldeville - That name's just a bit silly. The only way that name would ever come about is if English workers migrated to the island in the 18th century and decided to make every immigrant refer to the town as Oldeville sarcastically. Of course, for this to happen, the town style would also need to reflect something that looks like it's out of the 16th century. Towns are usually named based on local landmarks. Thornewood makes sense for a town built near a forest that had an infestation of brambles and other thorned plants. Little Stream is rather obvious in the same way - a village built on the bank of a small stream. Brookehaven similarly - a town built near a brook that was also in a suitable location for it to be considered highly defensible - perhaps in a glacial valley whose walls provide natural defenses. Queensdale also makes a lot of sense. "Dale" means valley, so a city built in a valley that also played host to royalty when they visited would likely be called Queensdale. When I'm naming towns, I think along those kinds of terms. Think of the original function of the town or any natural landmarks near to the town and work from there. If needs be, you can use words from other languages. The name of the town I live in for example means "Bridge over a river in a valley" in Viking tongue.
