Indeed, regulations will have to change before phage therapy is used. This should be done.
Re allergy: cite? It's of course possible to be allergic to other components of phage preparation, but I don't think anyone is allergic to the phages themselves. Many people are allergic to antibiotics, particularly those in the penicillin group.
While I agree the regulations should change I can't see the likes of the FDA changing anytime soon.
You can create anti-phage antibodies (here is a paper from 1933 on doing this [1], there are hundreds more) - if you can create antibodies to something then you can create an allergy to that thing.
Re allergy: cite? It's of course possible to be allergic to other components of phage preparation, but I don't think anyone is allergic to the phages themselves. Many people are allergic to antibiotics, particularly those in the penicillin group.