You may want to consider using a 'Custom Rewrite Provider' with the standard 'URL Rewrite' module. This would allow you to use an external file (published from Tridion) to manage the URLs. There are further details on this here.
There is example code linked to from that page for "Storing of the rewrite or redirect mappings in a text file". youThere is example code, linked to from that page, for "Storing of the rewrite or redirect mappings in a text file". You could publish these text files from Tridion. I am fairly sure from memory that the App Pool does not need to be recycled to pick up changes to the published files.