There is a traditional blessing a parent/father says for his children in many communities on returning from the synagogue on the nights of the high holy days or all Friday nights, etc. The text published in most siddurim comprises a fragment of a verse in Genesis (48:20) as well as the verses of the blessings of the priests (Numbers 6:24-26).
Halachic issues that seem to arise with this formulation are 1. the problem with reciting verse fragments (כל פסוקא דלא פסקיה משה אנן לא פסקינן ליה - "Any verse-break not according to the verse-breakup-up of Moses..."; see e.g. Tractate Megillah 22a) as well as 2. the apparent biblical prohibition of a non-priest using the priestly blessing (see e.g. Rama Orach Chaim 128:1).
Do any authorities specifically address these issues with regard to this tradition? Are there any alternate formulations traditionally used?