You have several possibilities:

1) Check the "Globally available" checkbox for the respective actions in the Custom Action Editor (=> in Prefs > Mapping > [App of your choice] > "Custom actions" entry in popup) and you can select and use that action anywhere. The application controlled by the Behaviour you added this action to doesn't need to be running.

2) Add it in the Behaviour Construction Kit > Action Factory and check the "Globally available" checkbox. Your action now becomes available everywhere (in the "Misceallaneous" category at Prefs > Mapping and at Actions > Miscellaneous at Prefs > Menu)

3) Create your own Behaviour using the Behaviour Construction Kit > Behaviour Factory, mark your action to be globally available and add your action to the newly created Behaviour. Then make sure the metadata is set correctly, so it doesn't depend on any particular application, compile, testdrive and install it. Just like in 1), you can now access your action everywhere in Remote Buddy, filed under the name of the Behaviour you created.

For step by step instructions, please see the Remote Buddy Help > How To section.

Best regards, 
Felix Schwarz