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

[Marianne S.]

No: HPFGUIDX 136101

JC wrote / asked:
> 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.

Marianne answers:

1) I think that 2 legilimens would be able to communicate without words. 
And if I see the path you're heading down... I think that they were 
communicating without words on the astrology tower, and that perhaps 
Snape was attempting to use occlumency against Dumbledore since the 
thought of (I imagine) "this is it.. now I have to kill him and even though 
that's what he wants it will change everything" was too horrible to ponder...
 and that's why the weakened Dumbledore who accepts Death as just part 
of the journey pleads with Severus... to kill him.

2) Yes, I think it is possible to cast a nonverbal spell while speaking an i
ncantation of another. I think this for 2 reasons. a) Dumbledore's reaction 
which has been written about many times here already) to the (supposed) 
AK seems to be in stark and obvious contrast to any other AK killing we 
have seen. b) It is impossible, we have learned, to effectively use an 
"unforgiveable" curse for righteous reasons. They just won't work as 
intended. So... if Snape was really doing what Dumbledore had requested/
ordered... I don't think an AK would have worked. It seems to me by 
Dumbledore's reaction to the curse that it is more likely that he was hit 
with "impedimenta" or something similar that would cause the already 
weakened Dumbledore to fall to his death -- something that would have 
hopefully been instant and without suffering. Therefore, Dumbledore has 
a peaceful look on his face with his eyes closed, rather than a frightened 
look with his eyes open. 

3) I honestly don't know of the general agreement on this board. However,
 it is the general agreement of my (offline) friends and myself that R.A.B. 
is Regulus. Those who didn't already think this way were duly swayed by me. ;)
So, if it turns out to be the general feeling on the board, I won't be surprised.

Marianne S