You'd set the language to German by adding default-locale="de-DE" to the first line of the style (the one starting with <style), though the Chicago Manual style will just default to German if you use a German Zotero version.

To get S. before the page number for in-text citations, replace the macro point-locators with this version.

<macro name="point-locators">
<choose>
<if variable="locator">
<choose>
<if type="bill book graphic legal_case legislation motion_picture report song" match="any">
<choose>
<if variable="volume">
<group>
<text term="volume" form="short" suffix=" "/>
<number variable="volume" form="numeric"/>
<label variable="locator" form="short" prefix=", " suffix=" "/>
</group>
</if>
<else>
<label variable="locator" form="short" suffix=" "/>
</else>
</choose>
</if>
<else>
<label variable="locator" form="short" suffix=" "/>
</else>
</choose>
<text variable="locator"/>
</if>
</choose>
</macro>

(the relevant part is the "label variable="locator" -- the style currently doesn't print that for pages, the above version removes that condition).

could you put this on gist.github.com (no registration required) and link to it from here? I don't like downloading things if I can avoid it.