No, you should not deactivate or delete the free Vimeotheque plugin after you install Vimeotheque PRO. Starting with Vimeotheque PRO version 2.0, the plugin works as add-on for the free Vimeotheque version and will add extra functionality on top of it.
If you do deactivate the free Vimeotheque plugin, Vimeotheque PRO will issue a warning in your WordPress admin pages telling you that it needs the free version. Except the lacking of any functionality of VImeotheque, your website will be visible and you won’t experience any errors or the infamous “WordPress White Screen of Death”.