Been running GS + Sword/Horn for a couple weeks now on my ranger. Your build looks like a very survivable build, good toughness, nice tie-in with the runes. The build should get more like 313/sec regen, though. You could get closer to 400/sec with a mango pie food buff (85/sec regen).
http://wiki.guildwars2.com/wiki/Regeneration: 130 + (0.125*656) = 212
http://wiki.guildwars2.com/wiki/Signet_of_the_Wild: 62 + (0.06*656) = 101.36
In my experience protect me isn’t reliable in a zerg (20+ enemies). Even with guard your pets are pretty likely to get taken down if you are running melee/frontline. If they are alive, it is usually with more like 1/2 hp, so protect me is good for 2-3 seconds of invincibility best case. If you happen to position your pet just right protect me can be great, but that’s really hard when you need the regen from guard NOW. In smaller fights, protect me is pretty awesome.
The other issue this build has is a lack of crowd control. In zerg fights that’s one thing you can do to make a huge difference between victory and loss. For a ranger that means at least either muddy terrain or entangle. Barrage is ok, but it doesn’t really replace those two, and you can’t take the time to channel that if you are front-lining it. You can also run with wolf or kyrtan drakehound for yet more CC. I tend to prefer muddy terrain so I can run RaO for stability. Otherwise the hammer train knocks me around like a ping-pong ball.
I’ve successfully run this in pushes through front lines, racking up bags, generally doing just fine in big zerg fights (20-30vs20-30, and bigger):
http://gw2skills.net/editor/?fMUQNBhYD7koiugbsQxCWLDIrC7R7RmIJYi7xogKh4JroKqA-jkCBoNCy0HwUBBKLqIasFhFRjVNDQFBTpaR12bAuEMa1yAYOGA-w
General idea is similar. Always up swiftness and regen with guard & nature’s voice. I was able to drop shout mastery because my boon duration is 45%. Runes of altruism apply might and fury to you (allies), so it is a pretty nice offensive buff when you drop your healing spring. Regen is about 494/sec, plenty of toughness, and plenty of ways to shed conditions. I keep a sigil of energy on the horn both to survive a bit more and to keep that extra 10% damage up more frequently.
