Personally, I don't agree at all about waiting for free agents after the draft. I feel like we need to go into the draft without any glaring holes so we don't have to over draft any players or get other teams jumping over us for the obvious players we would be going for to fill said roster holes.
That said, we don't have to go after the top name players to get solid roster players, and we all know Beane won't over pay market value on mid-tier players.
That way we can just go bpa and based on where we are drafting and projected boards that is likely wr in round 1. I also do not feel we need to draft a second wr that early though do agree about dipping back in and drafting a second wr in the 4th or 5th round. This guy will be a depth player who can play special teams and develop. Much like shorter will be after missing last year. In free agency I would at minimum pick up two vet dts hopefully one of them Daquan Jones and another a run stuffing dt, a vet rb for short yard/ redzone goal line situations, and a vet DE for rotation (two if we don't resign Epenesa). The DE's because DE's take time to develop and I would rather have a solid DE rotation we know is reliable rather than relying on a weaker DE class.
In the second I would draft the best C/G available (if any fall to us worthwhile like last year) for competition with Edwards and/or McGovern starting spots. Obviously if the player wins out at center slide mcgovern back over to guard. If there aren't any guard/ C that are worth a second round pick by the time we select I'd draft Safety as I do not agree with your assessment that this is a weak safety draft. I think there are quite a few good safety prospects who should be available at that 2nd round or third round selection position.
Personally, I would sign a safety in free agency to start and draft two young safeties one earlier in the second or third round if we go G/C in the second and then double dip in a later round for competition at both safety spots as well as special teams depth.
In the later rounds if we keep all our 11 picks (which is doubtful) I would go bpa while focusing on third rb, cb depth, the safety, a tackle for the oline competition, DT depth, the previously mentioned safety depth player, and the final picks bpa whatever position.