Yes and No.
Webshop+ 2 is designed to be an easy while flexible tool. so the answer to this question is a bit ambiguous.
If the only thing you want is to make very shallow and simple changes to the pre-designed templates, the answer is yes. Any average user of WYSIWYG Web Builder can perform this task.
If you just want to make substantial design and / or performance of the website changes, the answer is no. To make such changes, there is a necessary minimum of knowledge of PHP and jquery.