jazakAllah khayr for your effort. may Allah ta'ala reward you amply, because intentions are more important than actions.
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having acknowledged your effort, i wonder why should kanzu'l iman be translated in the first place? and if you read prof.faridul haque's translation you will probably agree.
the qur'an should be read and understood by all muslims [indeed, deriving aHkam or rulings is the domain of scholars with capability of ijtihad]. muslims all over the world speak different languages and it is unfair to demand everybody to learn arabic. yes, it is a great thing if they could, but unfortunately, reality-check says it is not possible, nor practical.
therefore some scholars translate the qur'an into their own languages for their own people. alahazrat raHimahullah did it for the urdu-speaking muslims.
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here is my contention: it is the qur'an that needs to be translated NOT alaHazrat's words. one can use his translation as a guide in difficult verses and confusing words but there is absolutely no need to translate it word to word.
alahazrat's translation is different from other urdu translations because he does not make a literal translation; the main reason stated is that the arabic idiom cannot be captured in urdu all the time. and sometimes translating the idiom might convey an unintended meaning. so he used urdu phrases and idiom to convey 'the meaning' of the verse.
now then, does it not defeat the purpose in the first place? alahazrat avoided a literal arabic-to-urdu translation because of the obvious pitfalls. notice that urdu is an arabic-oriented language with many of its words, phrases, idioms and even adages are borrowed from arabic. then is it proper to transfer it to another language that is not even in the same family?
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ideally then, a translation should be made from arabic to english by a person who understands both languages well. if an urdu-speaking person does this, it is an advantage to have kanzu'l iman of alahazrat. otherwise a translator is just another mufassir or an exegete and all the rules for a mufassir apply.
they should have a sound understanding of fiqh, usul, aqidah, arabic idiom, nasikh-mansukh, awareness of misunderstood verses by people gone astray [so that those mistakes are avoided consciously], have read major tafasir to adapt the meaning in the translation. additional qualifications are the most obvious ones: a good understanding of the original language, arabic, and a command of the language of translation - english in our case.
otherwise much will be lost in translation.
Allah ta'ala knows best.
wa's salam.
ps: in my opinion, you should not work with the constraint of translating kanzul iman. do a qura'n translation BASED on kanzu'l iman. and the readers must remember that alahazrat is not responsible for any of the translations.
