File associations on client PCs with RemoteApps

I have setup RemoteApps from a 2008R2 server acting as a Remote Desktop Server.
The client is a charity and volunteers will access the remote apps from their home computers.  
I am not clear about how file associations work where the following programs are available as RemoteApps: 1) A specialised "not for profit" database solution which keeps client records and associated documents, which could be Word, Excel, pdf and other types of file. 2) Word 2007 3) Excel 2007.
1. The remote user opens the RemoteApp database and selects a word document.  Does this trigger the local or the remote version of Word to open?
2. The user opens the RemoteApp database and also the remoteApp Word 2007.  Does this trigger the local or the remote version of Word to open?
3. The remote user opens the RemoteApp database and selects a pdf document.  Does this trigger the local version of Adobe Reader to open or is Adobe Reader expected to also be distributed as a RemoteApp?
4. The user opens a locally stored document for which the relevent RemoteApp is running.  Does this trigger the local or remote version of the app to open?

Thanks