Although a kind of reminder of latest names entered in the field would be nice indeed especially when, like me, you are setting the name to use the date and a letter to save the different instances/versions of your project (ex: MyProject_20170522.a)
+1 That would be nice if the field could remember the last used name.
As for overwriting existing local files, I'm not sure it's doable in a browser, maybe only in the standalone version later on. But I'm sure Ashley can elaborate on this.