what's the difference

hello,

Could you tell me the difference , if there is any, among the phrases below (assuming that all the phrases are correct)?:

1)...... the difference of using sth ....
2).......the difference in using sth
3).......the difference in use of sth....
4).......the difference in usage of sth ....
5)........the difference in using sth .......

and additionaly:
What's the difference between usage and use (when we use them as nouns).

thanks in advance for some comments!