How to use more than 2 versions on jquery?
Since you need to run multiple versions of jQuery for different contrib modules I would say the jQuery multi module would be the easiest solution (although I don't know the specifics of your requirements).

The 7.x-2.x branch of jQuery update is supported with jQuery multi.

For example, you could use Drupal default jQuery for admin pages, jQuery 1.7 for non-admin pages and jQuery 1.9 for the specific plugins/modules that require it.
Or alternatively you can use 1.9 as the main version and 1.7 for specific plugins/modules.
Whichever works best for your site.

Usage instructions for the jQuery multi module can be found in its README.txt file when you download it.