We were completely new to webshops and not satisfied with the themes offered by Shopify. A lot of functions we were looking for were not available and initially we started installing a lot of extra apps to cover required functionality.
Then we decided to look for a theme that gives us a wide range of functions right away. We chose Elessi 2.0 - and did not regret it yet (6 months later). Although the theme is not perfect - the code as well as the user interface are quite confusing and nested in some parts and it needs some getting into it - this theme gives you a great deal of customization options right away!
With the user interface most of your wishes considering look and feel can be achieved right away. For all the little details besides this it helps to develop some basic coding knowledge (I didn't have any of it a few months ago) - the theme includes so much potential functionality within the code already that even if something does not work out in the beginning, as soon as you can "read" the code, you can fix basically anything by copy/paste or similar.
Also the customer support shall be mentioned: Although they cannot solve each problem right away, they were very eager to please whenever we had an issue. They responded within 24h max. and didn't give up until we found a solution.
RESUME: Complexity brings some issues - in my experience this can't be avoided. Considering the potential for customization and the wide range of functionality of this theme it's really surprising though how well it works right from the start. I would absolutely recommend Elessi for everyone who wants an all-in-one package and is willing to put some extracurricular work into minor issues.