If site works okay will it be easy to upgrade to latests version or will it be hard and not compatible?
Hey,
If you have not made any changes on theme files, it should be fine. If you have, you may need to apply the same changes on some files such as header.php and includes/helper-main-menu.php files.
Your widget areas might be reset as well.
Please refer to this post – http://kriesi.at/documentation/enfold/move-from-a-local-installation-to-a-live-server/ and create a testing installation first and update there to check if it affects anything :)
Best regards,
Yigit