So to reset the root password, you still start mySQL with --skip-grant-tables options and update the user table, but how you do it has...
Change key Super that launches dash in Ubuntu First, disable the "Cmd" button, which likely corresponds to the Super (also known as Windows) key on other systems. This can be achieved with the gsettings terminal command:
Grub Customizer is a great application, it allows you to add or edit menu entry and change the default OS boot with GUI....
It sounds like you don't have the GD extension installed. I don't use Ubuntu any longer, but I think it may be named php5-gd,...