Firstly if you are using the PHPFeedback Form or SendForm actions then the page with the form on it doesn’t have to be called .php and if you do then you cannot view it locally (except using something like MAMP)
The only page that has to be suffixed .php is the form processing file (which is created by the Action) and will be called something like myformpage-go.php or FW_SendForm_myformpage.php