NOT A TEACHER
(1) Congratulations on your excellent grammar and wonderful attitude.
(2) Yes, you are correct: we all should strive to write the best
(3) I wish to point out a few minor points:
(a) Whenever I write, I struggle. I think that the present would be
preferable. It matches "write," and you are still an active writer.
(b) Again, I would suggest: But reading ... really helps me ....to improve
(c) I believe that the phrasal verb is "brush up on."
(d) Indeed, there is no other shortcut to mastering the English language.
By writing and rewriting, you will eventually achieve a polished product.