I truly believe that the visual aspects of the written word matters. The eye will always recognize shapes and visual patterns before it starts reading words. Ugly design will affect readers and can make a noticeably negative impact.
That said, there will always have to be a balance between being aesthetically pleasing and mechanically correct. I have noticed different habits and opinions when it comes to typed documents. Spacing between sentences, lines, and paragraphs varies wildly. Some people always put a period after dollar figures (so you know there are no cents afterward), and may or may not put a space between the dollar sign and the number.
Those are all aesthetic choices to me. They affect how the reader sees things, but none of them change the actual content of the words. When it comes to things like comma usage, or any other punctuation, those do matter, and they are non-negotiable.
You are not allowed to use a semicolon because it "felt right". It has specific uses with specific meanings. I you use them without any concept of how they are to be used, then you are unmaking the English language. (If you used them in a nonstandard way, but at least had a reason why, it would be a different story.)
Despite caring about the aesthetic of writing, the mechanics will always take precedence.