I have actually already purchased through Envato Marketplace the OpenPanel Plugin but I was wondering if there is any way to limit the amount the panels slide in over the existing page?
You can create panels as much as you want. So you can control and limit panel amount at a number you want. Example: If you want to limit 3 panels in a page you just add only 3 ones in that page.
Note: If you purchased the plugin, please add your license code: http://talk.sonhlab.com/licenses to get further support.