As already pointed out by several posters, it won't be very different from BM. You'll to quite a bit less damage, but you've already realized that. You'll get a lot of improved utility, but effectively it will only be a slight upgrade, since - unless you pull bad on purpose - you won't be using it very often. Later on you'll also get pretty nice mana management, at least if you've got decent crit rate.
I know you didn't desire this answer, but BM will get you to 70 slightly faster and a lot easier.
For leveling spec... I'm not extremely adept in the SV tree, however, I'd like to think I know the class as whole pretty well. This is what I'd recommend (note that you didn't say whether you were going SV/MM or SV/BM):
Short Version:
http://www.wow-europe.com/en/info/basics/talents/hunter/talents.html?tal=0000000000000000000000505201205010000000033103002510300313531300
TL;DR:
10-14: 5/5 in Lethal Shots.
15-17: 3/3 in Monster Slaying.
18-19: 2/3 in Humanoid Slaying.
20-22: 3/3 in Entrapment.
23: 3/3 in Humanoid Slaying.
24: 1/3 in Hawk Eye.
25: 1/1 in Deterrence.
26-29: 4/5 in Survivalist.
30-32: 3/3 in Surefooted.
33-34: 2/2 in Clever Traps.
35: 1/1 in Counterattack.
36-38: 3/3 in Killer Instinct.
39: 5/5 in Survivalist.
40-44: 5/5 in Lightning Reflexes.
45: 1/1 in Wyvern Sting.
46-48: 3/3 in Expose Weakness.
49-51: 3/3 in Thrill of the Hunt.
52-54: 3/3 in Resourcefulness.
55-59: 5/5 in Efficiency.
60-61: 2/2 in Go for the Throat.
62: 1/1 in Aimed Shot.
63-64: 2/2 in Rapid Killing.
65-69: 5/5 in Mortal Shots.
70: 1/1 in Scatter Shot.
As for Pets, in my opinion Owls are the best pets by far. They generate AoE aggro in addition to also mitigating damage with that ability. This will let you have Mend Pet ticking on the pet if you pull 3 or more mobs (however, as SV you're very much tempted to CC them all if that happends...) They also don't have the disadvantage of lower damage racial, like Carrion Birds, and you're able to choose from single-target aggro (Claw) and multi-target aggro (Screech).
However, Cat, Ravager and even Boar (due to it immobilizing the target when you pull it away) are all very good pets to level with. So are all other pet classes...
Oh, and making a NE is just fine... Shameful however, if you would've rolled a Gnome! Not that they can be hunters...