strict updates in iapp

Don't know about number 1.

While I don't fully understand the inner workings for question number 2, I've seen instances where additional configuration added within /Common/fred.app that somehow came to be - though are not part of the iApp, cannot be removed by attempting to delete the iApp. Then you have to hunt them down in bigip.conf and remove them manually. It's a royal pain. It would be nice if there was a purge option or something that just forcibly removes anything found to be left within the iApp directory.

If all you want to do is change a setting here or there, it's should be fine. Personally, I like to keep my iApps clean and reconfigurable at any time. It's certainly better to enhance or branch the template with additional features (if time permits).