You don't need a plate washer... just a heavy hex head nut. the depth is not to the end of the anchor rod, but, to the top of the nut... I typically use 18 x dia for 50 grade bars and 24 x dia for high strength bars, then, check them through my spreadsheet.
For anchors in tension, the only function of the concrete below the anchor rod is to protect it from moisture. My preference is 3", but in thin slabs I can live with 1".
I see you are concerned about side-face blowout. ACI 318-11 Section D.8 & RD.8 discusses this issue and addresses it by specifying a minimum edge distance for cast-in anchors (4*da for cast-in anchors that will not be torqued, and 6*da for cast-in anchors that will be torqued, where da is the diameter of the anchor). If you are concerned about an edge failure, provide anchor bolt edge reinforcement by using hairpins, ties, etc. in accordance with ACI 318-11 Section D.6.2.9. I was recently asked to review a splitting failure that occurred when a contractor was pre-tensioning anchor rods with sleeves for an equipment foundation. A splitting failure occurred during subsequent torquing and the edge distance provided was only 4*da. (Big lawsuit, be careful out there)
