I've taken a good look at the fixes. So affix is the general word for a variety of possibilities. And in this case we are talking of prefixes and suffixes?

Well, I was, though I gave no examples of prefixes, I was just trying to include other languages that might use prefixes to indicate smallness. This does give me a chance to define some terms.

One of the areas of intense research in linguistics is morphology (the study of (word) forms). First, linguists usually distinguish between inflectional and derivational morphology.

Inflectional has to do with inflections like case and number endings (e.g., -s as a plural ending in nouns, -s is also a third person singular ending on verbs in the present indicative).

Derivational morphology usually deals with morphemes (the discrete bits of words) that change the meaning or syntactic category (part of speech) of a root or word. Examples: un- is a common (or productive) prefix that usually negates the word it's attached to, true and untrue. -th was originally attached to adjectives to make abstract nouns out of them: e.g., hale and health, well and wealth. -ling is a diminutive suffix gosling, duckling.

Affixes: there are prefixes un-, re-, suffixes -hood (cf. German -heit), -ship (cf. German -schaft, infixes pretty rare in English, but common enough in Sanskrit where there are a few classes of verbs (conjugations) that have -n or -nV- infixed in certain forms of the verb. Other languages have circumfixes 'around the root'.

In your example of Dutch een klein huis 'a small house', klein 'small' is not an prefix but an adjective modifying the noun huis. I agree that "a small/little house" is rather neutral connotation-wise.

German and Dutch (and many other IE languages still have significant amounts of inflections in their morphological systems, but English has lost most of its. If you look at Old English, it looks more like German or Dutch in its inflectional morphology. We still have a bunch of derivational morphology. As Faldo mentioned above, -gate (from Watergate) has become a pejorative suffix, divorced from its original meaning of either a gate in placenames or a street (cf. German Gasse 'alley'). Something simular has happened to -burger in English, no longer meaning inhabitant of a city' as in German Hamburger 'a citizen of Hamburg'.

Your example of Dutch meisje 'little girl' is interesting. In German Mädchen, the -chen is a diminutive suffix and Mäd- does not exist on its own, in that form; there is the word Magd (cf. English maid, maiden) that is sort of archaic sounding (although in Bavaria, they still refer to a young women as a Magdl. I'm sure meis existed in an earlier form of Dutch, but for some historical reason has dropped out of the language. German -chen and -lein are interesting because they are actually composed of two diminutive suffixes a piece from -k-, -l-, and -n-. This was common in other IE languages, e.g., Latin homo 'human', homunculus 'manikin'.

Ceci n'est pas un seing.