Not being the author, I can’t answer your first question.
Not being a native Spanish speaker, I wonder the same thing. But a large part of it is “Would a native Spanish speaker, who is at an equivalent level of learning English, be able to understand the English version?”
And yeah, puns and homonym jokes don’t translate well.
I tend to wonder who translates them. I don’t think Bill Watterson is translating Calvin and Hobbes or Charles Schulz is translating Peanuts. Frank and Ernest/Justo y Franco is full of puns and sometimes has an adjusted strip because the puns don’t work.
The joke could sound offensive to a Latin sur-named individual. I know Baldo is a natural born citizen of an English speaking country and has a native accent, but there have been other strips where he is the target of discrimination based on his name and appearance.
Very poorly.