Please find attached sample workbook with 10.2 to your question 1&2.
I am not quite sure what you mean by combining 2 data sources, is it to combine your sample Excel files? If yes, you could use Union with Tableau.
Hope this could help
sample 20171027.twbx 16.5 KB
For Beginner Like me, I follow this blog when there is any issue with Combining or Union and Data Blend data source.
Let us know if you still struggling with your requirements, we are happy to help you.