TeXstudio seems to use the inputenc options to decide about encodings. Can this be disabled without disabling the encoding detection completly? As a lot users simply don't understand encoding issues I often get documents where the inputenc option is wrong. So I would prefer if texstudio only uses informations of the file itself to set encodings:
it can't be utf8 (or utf16) use (on windows) Windows-1252 (it would be ok if only the first say
500 lines would be checked for chars illegal in utf8)
use utf8 (or the setting in the preferences)
It's currently not possible to disable detection based on inputenc. But we can add that as an option in the future. Please post above text again in the feature request tracker. This will help us keeping an overview of user requests.