I won't speak to the viability of ranger in a zerg as that has been discussed to death in other threads in this forum and the ranger forum. I'm going to answer the OPs questions directly based on my experience. My strategy is to neither play in the back or directly on the front line during the initial push. Rather I'll wait for tag to push and then join the zerg 1 to 2 tick later. By that point you've avoided the majority of the initial bomb (so you don't die immediately) and you can provide some spike damage in the ball at critical times. You kind of play similar to a daredevil. Hope in, spike, then hop right out and reset. FWIW, I play a semi tanky boonshare build (not sure if boonshare is worth that much but I figure every little bit helps). I merge with my arctodus, hit endure pain and bear stance. Moa stance, warhorn 5, axe 3, Sic'Em, One Wolf Pack, hop in, Maul, hiltbash, wordly impact, maul and hope out. Reset and repeat. I can't speak to the overall merits to this method as a whole, but it works for me and I have fun with it.