Here are some ideas:
2 Skuntank is too many. You REALLY don't want to start a lone Skuntank (especially running no kind of warp like you have).
While I really, really like Sableye (and I really like to go first with Steelix), I don't like that it "needs" an unown q, and I really feel that Jirachi is about the only viable starter in this deck. I know, many will disagree, and I'm not saying the deck isn't any good without it or bad with 'tomb, Sableye, or Smeargle, but having played it ALL season, I really, really feel Jirachi is the only way to go. My downhill tumble in Texas states was a double flash bite KO, bright look Jirachi, Seeker Steelix, KO Jirachi ftw. Granted, I was pretty sure that was coming and I judge the turn before, but judge him into a GOD hand, not that it mattered, what killed me was that I was susceptible to the Seeker donk. Thinking back, I should have had an extra, free retreat, Jirachi on the bench and IF it was KO'ed, I got to search my deck. If any other starter sits the bench, it just becomes Bright Look bait and when it gets KO'ed to avoid Seeker, you just drop another and you won't get a prize. Just my thoughts...
13 trainers is pretty rough, makes Vilegar VERY hard. Winnable, yes, but KNOW the matchup VERY well.
4 Judge and 3 Volkner > any other Supporter line. Volkner lets you get rid of trainers, Engineer's doesn't. Judge will help keep your hand reasonable, paired with Nurse Call, you'll usually get more off of Volkner than Engineer, this will GREATLY improve your Vilegar matchup. When you get loaded and have resistance and only 3 cards in your hand, they will only net 10 damage on the high side and you can usually dump unwanted trainers from a hand like that very easy with Blissey.
4 Call energy is a MUST. Getting a T2 Steelix is imperative. Max out call and maybe even run a few energy Exchangers and atleast one warp. The advantage of Jirachi is that it lets you search out the "one-ofs." Running an energy lines that contain 4 call, 1 warp, and 2 exchangers greatly improves your chances of getting a call or a warp when needed, its almost like running 6 call and 3 warp.
After tons and tons of testing, I've found Conductive Quarry about worthless unless you are running Blissey Prime (which I don't recommend). In all reality, it serves Luxchomp more than it does you since most times, you won't lose Steelix, you won't need it. There are a few recommendations. Ruins of Alph is money, giving you the OHKO against Luxray (so will Plus Power). BTS is...interesting. While it helps your opponent as well, it also lets you lock up the "Stadium War" against other evo decks, meaning you will pretty much poison at will, allowing you to whittle at your opponent if need be. And, obviously, it helps you evolve faster. While it does have some advantages, I don't think its a must. The other Stadium I think that has some merit is Lost World. WHAT? I know. But, being as you don't really NEED any stadium, tossing one is for the Lucario/Palkia matchup is an autowin. If I ran one week one of states, I may have very easily have won that tourny. Instead, I dropped one to Lucario/Palkia and missed TC due to resistance. Is that deck REALLY worth teching against? Not really. But, it is one of the few stadiums that might help you and you NEED a stadium for Skuntank. If you run Jirachi and Twins, I highly recommend 1RoA and one Lost World as you can easily search them out and have no fear of needing to draw into them. Another advantage of Lost World is the ability to "lock up" the stadium against Lost Zone decks. Its not a HUGE advantage, but you can lure them into throwing that 6th poke in there on their turn, then judge them and discard the stadium. Now, that assumes it even gets that far.
As for "extra" power, I think you should run Plus Powers, but I think 4 is over kill. If there is any particular Pokemon you are worried about, a well timed Black Belt does wonders. Do the math, what is the highest HP Pokemon you will run into? Dialga g with 4 sp metals and belted is 180. A belted Machamp Prime is 170. A belted Ttar has 180. So, a belted Steelix with 2 plus powers and a black belt gets you to 180. Also, Black Belt is an awesome Blaziken and Garchomp counter. After Jet Shoot, Blaziken takes +40. A belted Blissey and a Black Belt revenge KO's Blaziken all day for one energy. For one energy and NO belt, Blissey and Black Belt OHKO's garchomp all day.
So, the secret to bringing it all together? First, Jirachi/Twins engine allows you to search out any card you will need. Second, Junk Arm makes Steelix almost broken (any deck, for that matter). Pair it with VS Seeker, this is a beast. Junk Arm/VS Seeker makes it to where you can almost always get back any Supporter you need. 3-4 Junk Arm, a VS Seeker, and 1 Black Belt, plus 4 Life Herbs and Judges make Steelix a beast to deal with. You can heal almost anytime you need,you can judge almost any time you need. you can Twins almost any time you need. And, you can fall behind a few, them drop a black belt and make a very quick surprise comeback, then VS Seeker for it next turn to do it again, its money.