I understand we'll probably lose Butler, but we have Michael Johnson and Phillips, who should be at least a solid safety duo.
We have much bigger needs at WR (depending on Plax), SLB, TE and OL depth. Safety should rank below each of those.
Regarding the FA signings, it's not inconceivable that one of the D-lineman will go on IR during the pre season. It happened last year to Osi. Even if not, we'll have the 'freshest' D-line in football, and with the talent we have there, it's probably the best too.
But if a player has to be cut/traded, hopefully JR can trade him to at least get something in return. Would Robbins, a WR (Moss, Manningham, Smith) and our early 2nd rounder get Boldin?