There are multiple issues with Moodle files containing empty or blank lines
(lines consisting of white spaces or tabs only) and/or white space before or
after the PHP open and close tags, notably with config.php and theme files.
Not sure if the hotpot module is converting ampersands correctly. $heading and $title are set up differently than in other modules: instead of outputting $course->title, a temporary $title variable is created and assigned that value. That made it difficult for me to decide whether it was already formatted elsewhere or not.
Also I didn't format_string() any of the variables included in $navigation rings, because I assume these strings get processed by print_navigation(), which includes format_string().
(While I was at it I also turned the autologinguests off for most module pages, except on the index.php pages and the view.php pages for those modules that allow guests)
iarenaza