My question Cannot create JDBC driver of class '' for connect URL 'null' java.lang.NullPointerException Tomcat 7 Hibernate 4 Spring 3 was closed as "Not a real question" without any comments from the users who voted to close it: Gamecat is Toon Krijthe, AShelly, and casperOne♦.
I edited it shortly thereafter and contacted those users to request they re-open my question. I received no response from them.
After much experimentation, piecing together the results of tons of googling over several weeks -- as no one result on SO or anywhere else seemed to solve the problem -- I finally found the reasons behind the issues I detailed. As the question is closed, I posted my detailed solution as comments on the question.
The issues and solutions I detailed would be of great use to SO users as just about every SO and Google search result usually ended with a shrug as no one seemed to know how to solve this issue.
Please re-open my question so I can post my detailed solution as an answer instead of as a comment.