(Edit: there should be a semicolon after 'ones' in the title.)
It feels wrong to me to consecrate someone else to the Immaculate and / or Sacred Hearts, and I'm trying to figure out how it makes sense. I can easily understand consecrating my child, but not anyone over whom I have no authority whatsoever.
Similarly, I wonder how it makes sense to pray to someone else's guardian angel, since as far as I'm aware, they have no obligation to me at all. It seems to me that it would be better to pray to the Queen of angels.