Actually quite a simple question, they are drill points and probably serve both artistic and technical purposes. Anything you see on a die struck coin would have to be in a negative on the die - in this case what you see as a protruding ball would be a small hole drilled (or punched, we know remarkably little about the tools people used for making coins) in the die surface.

This is not at all uncommon when engraving Greek on coins. Most Greek letters on coins are not cursive, they are made up of straight lines, so you can mark them out by placing holes at the points and then joining them together (note in the case you link that the cursive letters do not, mostly, have dots). You don't have to do this but I presume it makes it easier. And of course once you do it then other people making coins in the same tradition as you will want to do it - because coins are a very conservative medium, part of the way they work is to look like older coins (I touch on this at https://youtu.be/TwfMgeujQt4).

So you can find these sorts of dots on lots of coins all across the Hellenistic world. On the other hand there are absolutely coin traditions where people chose not to use them. So the answer is that we don't know in the case you are pointing to but it was definitely a choice.

Does wear make a difference?

The die the coin is struck from is fairly fresh, the coin is a little bit worn. Yes, both of these things can exaggerate features, they tend to flatten and spread things, but no, neither of them is the cause of the dots here.