Doing this by hand is very time consuming. An option for rename database would be great feature.
Also the ability to import databases that already exist on the database server into plesk would be great
Plesk also needs a feature to change the installed web apps database, for a Plesk installed WordPress app for example. In Plesk 12 if you create a new database, update the WordPress wp-config file to the new database, Plesk still labels the old database as "Used by an installed web app" which is incorrect. And you can not delete the old database unless you ssh in or use PhpMyAdmin.
Good idea this have happened to me before few years ago that I had to another way is to create another database with the renamed database transferred from the database that was not renamed. Rename database is a necessary feature.