Most probably you do not know what are you talking about. I know what I talk about.
You are not an hadith expert nor a good muslim with a good knowledge of the religion and faith. Yes I am not a hadith expert. Should I be one to quote an hadith? You can´t decide if I am a good or bad muslim. Only Allah can decide this. I believe I have some knowledge.
The only sunnah is the sunnah of Allah. Yes and prophet teaches us that.
Here is the hadith that confirms it:
"Do not write down anything of me except the Quran. Whoever writes other than that should delete it" (Sahih Muslim) Here is your answer:
http://www.hafizonline.com/makale_tr/hadis/hadislerin_yazilmasi.htm
As for your hadith, I do not know if it is authentic or fabricated (it must be fabricated if it´s narrated by Abu Huraira) What are your proofs?, but let´s say it is authentic..
اذكروا موتاكم بخير - (remember-your deads- with benevolence) = ölülerinizi hayırla yâd ediniz - talk good things of your deads
The part you translated as "your deceaseds" is "mevtakum" and indicates the dead people only you knew personally. I don´t think you are allowed to talk after a person because you don´t know him presonally. Talking after a person is not a good behavor.
Not talking bad things of your deceased father, mother, aunt, uncle, et cetera, is understandable but why should we do the same with all the others? It is an ethical value.
Why should I pretend to like them just because they are dead? If they did not want my respect in life, they aint gonna get it now. Hadith doesn´t say you should respect them.
Should not we talk bad things also about those evil men like Hitler, Mussolini, Franco, Stalin and many others just because they are dead? I don´t think this hadith includes blasphemers(kafir).
How could you explain this "according to your universal islamic ethical values"? Easily 
Wow vona you impressed me. At least your questions were decent. I answered your questions only for this time. Don´t ask me more about theological issues because I quoted a hadith. I will not answer these kind of questions.(I can but I won´t) As you say I am not an expert and I can make mistakes 
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Neden?