Hi Mark,
all i can say is… Use Webflow for design and code websites… that´s it.
Trust me webflow is a great tool and super powerful.
I designed websites and learned webflow. Last week i doing a test with a webflow designed website and the udesly adapter for bringing it to wordpress and it worked really fast and very well.
It´s good to know about html css3 it will help you and understand the webflow toolsbar better.
I coded websites by hand befor webflow and used other tools to design websites like adobe muse.
All i can say is that webflow brings super easy readable code out and make much things a way easier.
And by the way… It is so much fun to design websites in webflow!!!
cheers
martin