This article is lengthy, but helpful for /ploo/ vs /ploos/: http://french.about.com/library/weekly/aa101300v.htm
It depends. If I wouldn't say "for more details" as an English speaker, it wouldn't necessarily make sense to translate it that literally. I've largely heard this phrase used in instances where I would say "for more information." For example, when topping up my my phone credit in France, there were a recordings with a new offers for minutes or text messages that would say "pour plus de détails, taper un." The same announcement in English would likely be "for more information, press one." "For more details" isn't grammatically correct; it's just not used as often as other phrases. (Similar to how I've been taught it's not grammatically incorrect to say something is "fait de bois" in French, but nobody says that; everyone says "fait en bois," or whatever the material is.) That is, of course, my experience with American English; I'm not sure if any other Englishes are the same. I didn't put "for more information," because I figured it would be marked wrong, and I checked the discussion to see if anyone had thought the same.