@ nice gaijin
There are Western-Languages which have the "stressed"-thing, but still have slight tonal effect. This mainly occurs in some Western-Germanic languages, located in Western-Germany and Eastern-Netherlands and some parts of Flanders.
Example: Compare the Limburgish (Maastrichtian to be precise) "stein" and "stein" ("ei" is a bit similar to the Japanese "ei"). The two words are written exactly the same, but are pronounced differently. The first one, meaning (one) stone, has a long vowel which is pitched a bit higher in the end. The second one, meaning (two or more) stones, has a very short vowel.
So, it mustn't be too difficult for other Germanic (and Anglo-Saxon) languages to learn slight tonal effects. But I do think it's something that's almost never mentioned in language-lessons, although it should be.
About the vowel in Engrish: I think Europeans underestimate the difficulty for Japanese people to learn that syllable's don't always end with vowels. It's like teaching a French-speaking person to learn to pronounce the "h". (For instance, a French person would say "I 'ave 'eard of blabla....." instead of "I have heard of blabla..."). But as European languages are full of consonants, Japanese will have to learn to speak consonant-ending syllables, and syllables which have more than one consonant at the beginning (like the word "bread").