As for /p/, it is the case that if any voiceless stop is going to be missing, it is /p/, so the lack of /p/ does not require a chain shift. This implies that the creator of Dorfish is not linguistically naive, as a linguistically-naive English-speaker would normally include /p/.

And the language could just have a lot of words starting with vowels (which is not unknown in natlangs), because if all these onset-less words were due to consonant loss, either there was an overabundance of a small set of consonants which were all or mostly elided, or a wide range of consonants were elided partially, which is unlikely, as consonants being elided is most likely going to be highly selective.