Staraptor needs to lose Steel Wing. Use Close Combat instead.
Marowak is too slow to hurt most things, and too weak defensively to survive long enough to hit them (its above-average Defense is hurt by its terrible HP and below-average SpD). It should be relegated to a Trick Room team. Try something with a bit more speed or something; as cliche as it is nowadays, Scizor works well with Technician and Bullet Punch. Infernape can be a nice mixed sweeper, and Salamence is just plain deadly. Dragonite works nicely now that it has Extremespeed as well.
However, with Ninjask around, Marowak can be viable. You'll want to drop the Careful nature, though. Run Adamant with 252 Atk / 252 Spe / 6 HP. Consider dropping Lightningrod for Rock Head and Stone Edge for Double-edge - it's more powerful in the long run. Enemies behind a Substitute can put a damper on your sweeping fun - for this reason, Bonemerang is an option over Earthquake, although you'll lose some power. Finally, you can consider dropping Swords Dance for any of the three moves I just mentioned (Bonemerang, Stone (whichever); after Ninjask Baton Passes this guy a Swords Dance boost, it'll hit 1136 Attack total, or in less technical terms, fucking high. So Swords Dance probably won't be needed.
Swampert should probably abuse its defenses a bit more. Run an Impish nature, max out HP, and split the rest between Defense and SpD. As a note, splitting EVs equally between your two defensive stats usually turns out to be a bad idea - it's best to choose a defensive stat you'd rather focus on, and focus more on that. Also, Waterfall is a better choice than Aqua Tail. The slight boost in power is not worth the accuracy drop.
... A sweeping Tentacruel? That's not a great way to use Tentacruel. Its SpA is too low to be a really effective sweeper. It works best as a supporter. It can set up Toxic Spikes, use Knock Off to remove Leftovers from walls, hit opponents with Toxic, and even Rapid Spin away entry hazards. Drop the Scarf altogether, and run Calm with 252 HP / 136 Def / 120 SpD. For the moveset, run Surf and whatever support options your team needs most.
Snorlax has a good STAB that I think you should consider abusing. For starters, Careful is a better nature, as Curse will be boosting your defense quickly anyway. Putting EVs into Attack is questionable, since, again, Curse will be shooting it through the roof, and it's already above-average anyway. Switch some of those Attack points into HP and put the rest into your other defensive stats. Rest is important as it's its only recovery move. It'll also remove the need for Immunity, so you can use Thick Fat and gain a resistance to Fire and Ice, two common special attack types. Return is a good option for STAB, but Body Slam can paralyze opponents, which is a nice bonus. The last move you should use depends on what your team has the most trouble with, but generally it should be able to hit Ghosts, because otherwise they'll wall Snorlax entirely. Earthquake hits Steel- and Rock-types, but a lot of Ghosts have Levitate (Gengar, Mismagius, etc.). Fire Punch hits Steels and all Ghosts, but then Rock-types wall you. Crunch hits Ghosts for super-effective and Rock-types for neutral, but Steel-types will wall you.
Ninjask is the main reason you need Rapid Spin on this team. Either lead with Ninjask (which is a working possibility) or make damn sure your opponent doesn't keep SR up for long. Now, Protect is a good option on this guy because it lets you stall for a few more turns and get a few more speed boosts to pass around. Dropping X-Scissor will leave you at the mercy of Taunt, however, so be careful. If you use this as a lead, try using a Focus Sash instead of a Liechi Berry. That way, you can open the match with Protect, Swords Dance as Focus Sash kicks in, Protect again, and then Baton Pass. That will net your next switch-in +3 Speed and +2 Attack - enough to make even the ultra-slow Marowak an offensive beast (472 Speed and 1136 Attack is basically "gg"). I'm pretty sure Marowak can also survive things like a Scizor's Bullet Punch, although I can't give you a calculation on that.
