The suggestion really isn't something the Administration can handle, you're suggesting some sort of Modification etiquette that not all coders/designers will follow...I don't think it's possible (or fair) for the staff to enforce them.

Also, I want to go further on Roms point - even the most expert coders rely on testing by users who install their modifications...a single coder can only test so much given the countless amount of variables that are involved with using a modification:

Server details, vBulletin version, other modifications installed that may cause compatibility issues...etc...etc...

Finally, the user will always have to do research before installing a modification on their forum. Part of that means going through the thread and investigating if there are any lasting issues with the modification in question.