Obstacles don't protect characters from things, and ranged characters other than snipers can't fire around them. Melee characters on the other team can hit the character behind the obstacle just fine.
My point about Ghram Rager is how fast it comes into play. Its a 1,1 that costs the same as Quick Shot, does the same damage, but can also be improved. I've been wiped by beast deck when it gets the right combo out in the second or third turn and starts playing 0 and 1 cost cards that get to attack immediately, receive bonuses for being beasts or other buffs, and manage to keep me from keeping anything on the board long enough to attack.
I've gotten a little mileage out of the Enforcer, I think its particularly interesting how different your strategy and impression of the value of different cards is than mine.
I thin my deck out before leaving the starting camp, usually to 15 or 12 cards, holding back almost all the 5 cost and most of the 4 cost cards. I keep usually one 4 Momentum card and one Warrior Monk, a 5, but I focus my deck on 2s and 3s. Depending on draws, I usually keep it cheap and fast. For equipment and skills I look for Armor and low cost abilities, I avoid the machine gun and the beam laser and they usually don't pay off for me.
In play I discard anything I can't bring out at the first or second turn, I usually prefer to see a wild hand or a sapper. My best play is with lots of low cost cards reinforced with cards that improve all of them, and protected with a Taunt. I prefer to whittle down the enemy before the momentum is high enough for them to bring out anything I can't handle.
That's the strat I've developed so far. I've been dealing with each of the factions I've met fairly consistently. I think it speaks to the game design very strongly that multiple strategies are valid, and that for them the various cards have different merit. For my strategy, the Enforcer is so expensive that I likely won't be able to play it, and it would do too much damage to the cards I'm using at the time.