footnotes added if there were puns. Not too hard.
Mybe not hard - but absolutely deadly
to the fun of a joke! The lengths you'd have to go to explain a pun that's taken place in a foreign language would undoubtedly be beyond the capacaity for the margins of a children's comic to contain - plus you would have done nothing to convey that the original remark was there to make someone laugh
. Translation isn't about just slavishly making matches of words, it has to contain the same emotion and sentiment as the author intended.
Hergé names a place in Khemed "Bir El Embik"; that's a punning reference to "bier Lambic" and "bir 'al 'iinbiq", the Arabic "Well of Al-Anbiq". By the time that you had explained what each of these is, and how they interrelate to make a pun, you have really not a hope of holding your audience.
However, by rendering this place as "Bir Keg" in the English, you hold onto the most significant parts of Hergé's text - that an Arab well combines with beer to form a joke, and you are done and dusted: no footnotes, no explanations, and a laugh!
In the English translations, Marlinspike is in England and Haddock is English. Tintin's origins, however, remains vague.
There isn't actually anything in the English editions which says that Captain Haddock is English, per se, nor even that he is British; in that respect his origin is as vague as that of Tintin...!