2 questions that might clear a lot up and a 3rd for verification.

[genesis_wave]

No: HPFGUIDX 136084

1.  Would it be possible for two strong legitimance practitioners, 
such as Dumbledore and Snape, to communicate with each other without 
having to use words?
2.  Is it possible to cast a nonverbal spell while speaking the 
incantation of another spell?
3.  Are we in general agreement that RAB is Regulus Black until JKR 
says otherwise?

JC.