What makes a good writer... of course it's all a matter of opinion, but i think you must have mastery of the language in which you write before you can attempt to manipulate it to express your ideas in your style.
i do not agree that improper grammar- when not used knowingly for effect- is acceptable. That can ruin a story for me. i have never been so engrossed in any writing that i did not notice technical errors. But maybe i just love to proofread... lol...
i'm sorry, i don't remember who made the comment about e.e. cummings purposely using lowercase and lack of punctuation to make a statement- yes, yes, yes!! you are right, so i won't repeat.

i also find that the more i read, the more my imagination grows and the more i become aware of and develop my own different writing styles.