I fear your translation is a bit long for us to proofread and give meaningful feedback. Since Toritoribe-san is the only native Japanese speaker on the forum, the onus would be on him to either take on this project, or to re-proofread any attempts us non-native speakers could make. (Actually we have one other native Japanese poster who regularly seeks advice on English teaching topics, and this might be a good project for him, but I forget his name).
Anyway, from a very detached perspective, your translation is a technically faithful attempt to translate the source, but it us unnatural, and in a couple of cases where the original sentence is long with multiple clauses, it ends up as very confusing Japanese, and might be better off being broken up into two sentences, or slightly modified so that the point is made without adhering to the strict syntax of the original. So repairing these sentences or suggesting alternates is a bit of hard work. For example, the title itself "About the journal" might be better translated as 本誌について, which moves it from the abstract 雑誌 (all magazines and journals) to the specific "THIS magazine".