That pic must be very misleading...in a side view I think you would see that I have very little arch. Just the natural curvature of someone with his/her traps tucked tight.
Yeah, I just want to bench the safest way... or at least moderately safe so as not to fuck up my shoulders too much. Arched back actually helps safety wise? Hrm... I dunno, doesn't seem like it would, but I guess I'll take your word on it B.