The WordPress host here at St Andrews has been set up to use your University login.
WordPress websites at St Andrews are provided on a “best effort basis”. You agree to the terms & conditions by signing up – there’s more info here: http://wp.st-andrews.ac.uk/tandc/
For security reasons, if you’d like to install anything which isn’t installed by default then it needs to be requested through IT Services – send them an email referencing the site URL/address and the specific name of the plugin or theme you’d like to install.
If you’d like to create your own WordPress theme from scratch (you will need to know PHP, HTML, CSS) you will need to pass the files to the IT Helpdesk to have them tested before they can be implemented.
There are some basic FAQ answers and some guidance here: http://wp.st-andrews.ac.uk/frequently-asked-questions/