Yes, minor updates that do not induce a change of version (for instance 1.1 to 1.2) are free of charge upon request and proof of purchase (your invoice) ; major updates (for instance 1.4 to 2.0) which constitute major changes can be purchased from the Modules tab of our website (http://www.storecommander.com/fr/modules-prestashop/307-module-terminator-31-pour-prestashop-15.html).
Yes, Terminator is a classic Prestashop module and can be installed locally.
It is a global removal of all orders and all linked elements, impacting a few tables.
It is advised to keep and to empty the cache only when changes have been made to your template.
Terminator optimizes all tables at once. If you have only a few options on your hosting site and you have access to phpmyadmin, you can select and then optimize tables by groups and their sizes. Once logged onto phpmyadmin, select the database to get the list of tables, select a table group, or all tables and then deselect the bigger tables, and click on 'optimize' at the bottom of the page. Here is a technical explanation: http://dev.mysql.com/doc/refman/5.0/fr/optimize-table.html. Phpmyadmin shows the 'lost space' on the right-handside in columns when displaying tables. If the value is important, this is when you can use this tool.