visa query about forms for my application

Hi, I am traveling to China as a tourist for 8 days in April. I have filled out the visa application form but I was wondering do I need to complete the supplementary visa form aswell? I am currently teaching in Abu Dhabi and my nationality is Irish. I will be traveling from Abu Dhabi to China and returning to Abu Dhabi.

Also can a friend drop my application into the office and collect it on my behalf ad I will be working?
and finally is the cost 100 ADE?

Thank you for your help
Kind regards
Lisa Mc Hale