Good call @jk. I think that we should probably remove the whole concept of being able to remove apps by touching the installed version in the list, and only allow it from the menu. Having said that, I'm going to remove the "critical" tag, and replace with more specific ones, as it is not crashing or preventing people from using F-Droid to the point where we will be putting resources to this over other bugs. I do understand your point about deleting data, but we'd rather save the critical label for things such as not being able to download or install apps at all. Cheers.
It does indeed ask. "Do you want to uninstall this app?". So you can call this a UI/UX issue, but it's definitely not a security issue/bug since we are warning the user anyway.
Android is asking, not F-Droid. But when you use F-Droid with system permissions (for example when injected into /system partition), this system UI is bypassed and there is no question. Both clicking installed version in list and uninstall button in toolbar does the same.