I think there should be an easy way to reset or reload default templates and then assign them to corresponding page types. Also, when I installed DMS there was no template for the blog page or single post page assigned to these page types.
This would save a lot of time if something goes wrong or you want to start from scratch.
Another thing I found strange is when you use the plugin that shows what template is assigned the page, it sometimes says CUSTOM or some other "non existing" template ( at leased it's not in my library). Why is that?