Unable to reset/change Default Font size. I am able to save the font per the instructions but it does not save the font size. How do I get it to default to something other than Ariel 9 point?

with nothing selected click on the text tool. Don't click on the page. Just set your parameters in the  top settings and it should pop up with a defaults dialogue. Check both "artistic and Paragraph text and hit ok. Then go Tools/Save settings as default. 

Default Object Properties are controlled by styles, and you can set them in the Object Styles docker:

When you have "Artistic Text" selected there, then changing the properties in the lower part of the docker sets those properties for new Artistic Text created in that document.

If you want to save it as the default for Artistic Text in new documents, you can right-click on "Artistic Text", then click on "Set as New Document Default".

Style sets can also be imported and exported in that docker. If you are working with an existing document, that allows you to import a bunch of styles for default object properties all at once.