Nice topic
I think the difference between use and usage is quite big
For example, we say, Do not use this tool, Its dangerous
In the second condition we say,
The usage of this tool is very dangerous
Here we find, In the first condition we've specified the subject
while its an opposite in the second condition we haven't mentioned any subject
thanks a lot 
يا ايها الرجلُ المعلمُ غيرهِ..............هلا لنفسكَ كانَ ذا التعليمُ