I started to rewrite Opencart 2.1 template classes with my own classes (I'm front-end and want to use my shop also as portfolio).
When I started to add modules I found out that probably it can be not the best idea taking in consideration that all modules use standard opencart styles to rewrite it via OCMOD. And I will need to make changes in all modules I add also.
I'm bit confused, so my questions are:
Thank you!
You shouldn't remove the opencart's classes, you should add your extra. The main reason is that if you going to install any extension that adds a functionality into your eshop, then it won't render properly into your template and you will need to change it's code too.
As for the question of "better and smarter" way, I can't understand what you mean.
OCMOD will rewrite the templates but it will never rewrite the css files. So you will need extra css files.
Suggestion: Keep the default theme and extend it or create a new one based on the default template.