As a general rule, I translated the names of non-human beings to an approximate English equivalent. This is in line with my even more general policy of translating everything unless it was really impossible. Of course, the names of non-human beings in Pali only map very loosely onto those in English; but it is worth bearing in mind that the English meanings also change drastically, as do the Pali. An obvious case is yakkhas, which in later literature typically have a negative sense, a ferocious demon, but in the suttas is most often ambivalent if not positive. Thus using the Indic term can be even more misleading, so I have used “spirit”.
In the case of nāga, we find four main meanings:
A large snake, probably king cobra
A powerful and dangerous non-human spirit in serpentine form (“dragon”)
In metaphorical sense, a “spiritual giant”.
In MN 23, there is series of interesting metaphors, each of which can be read on multiple levels. On one hand, of course it is to be expected that a snake would live in an ant-hill. However the border between an ordinary snake and a mystical dragon is far from clear-cut. It is common in modern Hinduism to find nagas worshiped in an anthill. Given that the Buddha identified it with the arahant, it seems a better reading than “snake”.
In Majjhima Nikaya 142, Dakkhinavibhanga Sutta, there is a typo at the very end. The sutta ends with 5 short verses. The third one pertains to a gift being purified by neither the giver nor the recepient if both persons are of immoral character. It reads:
When an unethical and untrusting person, gives an improper gift to ethical persons, not trusting in the ample fruit of deeds, I declare that gift is not very fruitful.
But actually, it should read like this:
When an unethical and untrusting person, gives an improper gift to unethical persons, not trusting in the ample fruit of deeds, I declare that gift is not very fruitful.
In Ven. Sujato’s translation of DN 31, in the section regarding the five duties of a parent to a child, only four are listed. Arranging a suitable marriage is omitted.
Parents served by the children in these five ways show compassion to them in five ways. They keep them from doing bad. They support them in doing good. They train them in a profession. They transfer the inheritance in due time. Parents served by their children in these five ways show compassion to them in these five ways
In An 7.50 (german) there is a typo: “Keuchheitswandel” instead of “Keuschheitswandel”. This typo seems to occur only once. update: it occurs already in the database at palikanon.com (which has the same translation, but differs in numbering: it is “AN 7.47” there), and only once.
This lets make me the suggestion to run a word-statistics program over, say, the german database and check any miswritten word by the frequency/occurence table (I've done things like this sometimes in my job and for finding obvious typos/false links in the palicanon.com-database)