Are there any URL shorteners or redirectors whose target links can be changed by its creator after it was made?
Not Long claims to be able to do this.
They have a comparison page and editing is one of the things they compare and highlight as a benefit of their service.
Snip URL allow editing if you register.
Snipurl allows links to be re edited. This is a versatile site with many features, well worth a look. You can choose from several prefixes for your links.
The stats are basic, there are no graphs.