Question: I have very little PeopleSoft experience but have been put in a position to support an install. This question could straddles serverfault but is certainly developer oriented.

On a daily basis, we have a PeopleSoft "developer" who writes scripts to fix records/journal entries/approval status etc. To me this screams "bad install" and botched customizations. Is this normal? Is it best practice to have an employee having to write scripts daily just to keep things running?

Note: there is no fraud happening here, he has the full approval of the accounting department when doing this.

Answer: 
It is unlikely that it is the installation. Likely causes:

1. Bad customization
2. Missing patches
3. Bugs in the delivered code

If you only have one admin, though, and you have only one developer, I would be shocked to hear that there is much in the way of custom code.

Back to the question: It is not normal to need to do SQL updates regularly to fix data. Yes, it happens, but not too often. It is also possible that the end users could fix it from the application, but do not for some reason.
Ad-hoc SQL updates can be dangerous and the SQL may change on every request. It is difficult to fully test ad-hoc scripts due to the turnaround they typically require.

I assume these "fixes" are in fact making changes not implemented by the system.
It would be more sensible to either:

* Build a custom page to "fix" the entries (or less sensible: modify the delivered pages).
* Build and thoroughly test a paramater-driven App Engine to perform the most commonly made changes. It could potentially be run as part of the batch stream.

Watch out on your next upgrade: application tables have had a lot of changes in recent releases.