I understand the Greek dilemma. I suppose the only real solution would be to use a Euro cent symbol instead of lettering. The numerals are universal amongst the Euro countries, so that shouldn't be a problem.
No reason to use a cent symbol. The official names of the two units, in singular and plural, are "euro" and "cent". If anybody - whether in the euro area or elsewhere - wants to adapt the terms to whatever is preferred locally, fine. So let them use "euri" or "euros", "centime(s)", "eurocent" or "sentti". In Ireland some like to append a plural-s while others don't. Here in Germany some pronounce the small unit "tsent" while most say "sent". So what?

So the coins will say euro/cent, without any regional variations. The only exception, as Peter wrote, is euro countries that use "non-Latin" characters. So Greece (with the Greek alphabet) and later Bulgaria (with the Cyrillic alphabet) may repeat the face value on the country-specific sides. Austria currently does it too, but if they ever modify their national sides, that would need to be removed.
As for spelling errors on coins, one came up a few days ago in a quiz question: The hexagonal 2 fr coin minted in Philadelphia for Belgian Congo (1943) said "Belgish" on the Dutch language type, instead of "Belgisch".

(Image: worldcoingallery.com)
German coins from Baden said "Grosherzog" instead of "Grossherzog" (Grand Duke) until 1907. But that was not a spelling error - just a regional variety. And then there is the Johannes Brahms collector coin that the GDR issued in 1972 - no spelling error but it depicts notes from one of his symphonies, and one of the five notes is wrong ...
Christian