Modern Standard German (as well as most central and southern dialects, including Swiss German) has indeed the cross-linguistically extremely rare affricate /pf/. It corresponds to /p/ in other Germanic languages, including English. As an example, compare German "Apfel" with English "apple". However, word-internally, in most positions (the word "Apfel" is a bit of the exception from the rule here
), the /pf/ was historically de-affricated to /f/. An example of that would be German "Waffe" versus English "weapon", or German "schlafen" versus English "sleep", and not
*Wapfe and
*schlapfen.
In German, this occured in concurrence with the Upper German consonant shift, by which Proto-Germanic *t became the affricate /ts/, and Proto-Germanic *k became the affricate /kx/. While the former also occured in Standard German (eg. German "zwei" or /tsvaɪ/ versus English "two"), the latter however did NOT occur in Standard German, it only occured in some Upper German dialects (like Swiss German).
As for Etruscan, would suggest that the Etruscan Phi <φ> represented the same affricate /pf/? I thought the consensus opinion was that it represented an aspirated /pʰ/, just like in Archaic Greek (in that scenario, Theta and Chi in Etruscan were pronounced as /tʰ/ and /kʰ/, respectively). If Phi was pronounced as /pf/ the question would arise what Theta and Chi were pronounced as, so, in my opinion, this may
not even be a coincidence, but two entirely different sounds altogether!
Another problem - for Etruscan to have any influence (subrate-wise) - is the timing and the geography: the Upper German consonant shift started occured at the conclusion of the migration period (only the continental, West Germanic languages participated in it, and only the southern dialects of German execute it fully). By that time Etruscan was long-since extinct. Additionally, the area of German where /pf/ is used does largely not match up with the area where Etruscan was spoken in Antiquity (Gaulish, mostly, if people didn't speak Proto-Germanic?). The only area of overlap is South Tyrol, if Raetian (the Etruscan-ish language that was spoken there in the Antiquity) is included.