Yes, based on Phar's Knowledge (arcana) roll, the paragon elf can tell that a scorching ray spell isn't going to hurt Galzadar with the protections that the 'other' elf wizard has up, so, logically, Phar would not fire at him with the spell.
Instead, we can say Phar fires the rays at one or two of the rooks. Note that Phar must either cast defensively (a Concentration check [DC 17]) to avoid taking AoO from the rook that is threatening him or make a 5 ft. step away from the rook. There is space (barely) next to Aureus for Phar to step back down the slope, so he can make that 5 ft. adjustment.
I will assume that is the case.
Both rays hit. I will say that Phar targets the rook that was closest to him. The scorching ray puts that rook down. The second ray puts down another rook as well.
EDIT: And I just notice you already changed your post to have Phar fire at the rook. Heh.