Is there a way to change the footer font size in Impress?
That can be achieved using Slide Masters. First make sure your Task Pane is visible, View → Task Pane should be checked, then click on Master Pages in it. There you can add more masters if you like, and after making adjustments to them choose which one to apply to which slides (right-click on master page for options). If you need the same footer on all slides, one master page will do.
Then go to View → Master → Slide Master, click on Footer Area at the bootom of master page, select the text and use Font Size drop-down list from Formatting Toolbar or right-click on selected text then Character to change its font size.
Thank you, it works. However, In LibreOffice 4.4, making multiple changes to the font crashes LO.