Re: Usage of Brackets to enclose additional information
Perhaps I am not the best person to answer (I have to force myself not to use brackets as often as I want to) but brackets can serve a useful purpose in the way you suggest and, if used sparingly, they are an aid to the reader.
PS I have to say that in order to improve your English, ... , you should try the book, "Oxford English Grammar". English and titles are capitalised.
"There are no rules in English, only guidance. Some guidance looks like a rule; it probably isn't."