First and foremost, if your friend wants to play with Goblins competitively, he needs to make the jump up to Food Chain Goblins. Vegeta2711's excellent primer is a good place to start:
http://www.themanadrain.com/primers/fcg.htmThe problem with Sligh these days is that it simply cannot kill as fast as it used to, and it can easy be hosed with Chalice or 3Sphere. Most decks now have a fundamental turn of 2, Sligh usually is setup for its kill on turn 3.
That being said, I still love playing Sligh for mindless fun. So I'll try to give your friend some advice, if I'm way off base on something I'm sure someone will come along and correct me. Here we go...
Why only three fetchlands? This is the one deck that wants to take advantage of all 8 fetches. They also help get your Barbarian Ring online faster, even though I'd say running just 1 is a bad idea. I would cut it, as you'd normally want to have them dead before you hit threshold, otherwise go ahead and run 4.
Shocks over the fourth Fireblast and Incinerate? Definitely cut the Shocks, and add the last Fireblast and Incinerate. You should also probably be playing with 4 Goblin Grenades, and the 4th Reckless Charge is also worth looking at, although everyone has a different opinion on it (I say no Charges).
Jackal Pup and Goblin Cadets are definitely 4-ofs, no question. Cut the Ball Lightnings, as they're just a Drain target and lack synergy with the rest of the deck. Add 4 Goblin Piledrivers, 4 Goblin Lackeys, and 2 or 3 Siege-Gang Commanders.
I find Cursed Scroll to be too slow, and easily taken care of with all the Null Rods and artifact removal running around. If you feel like you need the board control, Lavamancer is better (this is another place where 8 fetches help a lot, if you go this route).
Cut the Strip and Wastelands. I think it's pretty critical to make your first three mountain drops, and this deck isn't trying to disrupt your opponent, just kill them. Also cut Fork, Fork is a reactive spell, and this is the furthest thing from a reactive deck. I also agree that Wheel of Fortune is bad, other decks will be able to take better advantage of it than you a lot of the time.
I've tried to keep my advice pointed towards a direct, balls-out aggro deck that will have the opponent dead on turn 3 or 4. I don't think it's as competitive as it used to be, and maybe there is a compromise that could be made (with Null Rods, Strips) that would help it out in certain metagames, but that's for someone much smarter than me to say.
Hope that helps.
