Definitely a tough one and realistically I hate to admit it should probably stay as it is to reach the widest audience. Also funny that the original post for the topic clearly meant suffix and omitted the vowels and extra f, but chose sfx which obviously has its own meaning and totally changed the direction of the discussion.
But 'on topic', personally I would prefer titles, honorifics, etc. to be expressed with a semblance of their original form because it is difficult to always translate the meaning into English well--and therefore more meaning is preserved with them; however, as indicated by @myskaros, it's true that prior knowledge is required to appropriately make sense of them and there is absolutely no consistency in available prior knowledge. As such, I can only appreciate the efforts to make translations make sense for the widest variety of readers. If new people can't get into the novels because there is too much "jargon", it only hurts everyone who wants to read them in English.
As far as sound effects are concerned, I've gotta say that @liz pretty much nailed it. (Which is good since (s)he is a member of the translators group). Although, you could always do both with the rain example? ...Leave the sfx and also include something like "...the sound of heavy rain could be heard pelting the ground..." in order to both maintain the author's original intent, building the scene in a way that is more flexibly interpreted, and also help to introduce (or reinforce) the reader's knowledge of typical sfx selections in Japan.
Anyway, not sure why I bothered to write so much--just got into rambling... but figured it'd be nice to chime in on the conversation.