>if original is bad, translated original is better - can the translation itself then be called good ?
>Should a "true" translation stay at all the levels of the original ?

Didn't say the original was bad - if it was, how could it inspire the translator? It's just that the original didn't live up to expectations I had after the excellent translation. Felt sort of let down. Happened a few times, and I remember those cases because they were so rare.

>In a few years google might succeed at enhancing such levels as well, as quality of machine translation is now good enough to render most articles I throw at it at least understandable.

Perhaps for the english-german pair. I tried serbian, "izuj limara", for which the only correct translation is "take the footware off the sheet metal worker". It gives me "take out the tinsmith". "Potrti" (to cancel out) it translates as "rub", because "trljati" is "to rub", but it's still quite wrong.

Couple of years ago I tried with dutch-to-english, and found out that the translation almost makes sense. It helped that I knew the context and what typical errors may be, so I wrangled some sense out of it.
The trouble with machine translation is english, the language of ambiguity: http://ndragan.com/lange/dvosmisleno.html