Metagross is a force to be reckoned with, but I'd think twice before using Rest. These days the game is just too offensive to risk sleeping for two turns. It's also setup bait if you don't have Sleep Talk (and even if you do, there's a 1/3 chance Sleep Talk will choose Rest and do nothing anyway).
Well, as promised, Sakura, here are my thoughts on your team members:
Feraligatr:
Nice, although you'll need an opponent reasonably slow to get the jump on them. I would HIGHLY recommend axing Crunch for Ice Punch (Platinum/HG/SS Move Tutor). You have plenty of Ghost/Dark attacks in your team already and no Ice attacks. Feraligatr isn't really fast enough to get the jump on a Dragon, but it's still nice coverage against Flying and makes Grass think twice before trying to set up.
Absol:
Super Luck, nice. Sucker Punch, as previously suggested, is a great idea since it'll compensate against faster opponents, and Absol has the attack strength and STAB to use it exceptionally well. I'm not sure how much good Psycho Cut will do you; Absol's defenses are poor and his speed not impressive; he should not be staying in battle against a Fighting type. Ever. For the same reason Swords Dance's usefulness is a bit limited; you need to be darn sure that it's safe to power-up (on the other hand, Sucker Punch when you know an attack is coming and Swords Dance when you know one isn't could work well). I would also seriously consider Superpower (Plat/HG/SS Move Tutor), as it'll prevent Absol from being completely walled by a Steel type.
Blaziken:
If you're not running any non-attacking moves, Blaziken may be a good candidate for a Choice item. Your team consists mostly of medium-speed heavy hitters, so you might want a Choice Scarf here to mix things up. Blaziken could work great as a revenge killer (be aware, with Adamant and not Jolly, there is the off chance that some of the exceptionally fast Pokemon, if also having a Speed boosting Nature, may outrun you anyway; this includes Jolteon, Aerodactyl, Crobat, and Mewtwo). Consider Flare Blitz/Brave Bird; I know recoil is a concern, but that level of power and accuracy can be well worth it.
Lucario:
Plenty of room to experiment here, since there's a lot that Lucario can do. Since you're going the special route, Vacuum Wave, Dragon Pulse, and Flash Cannon are all alternatives you might want to consider. Calm Mind is great, but I'd consider axing Psychic. Lucario is completely immune to Poison, and if stuck against a Fighting type, you'd be better off switching to Salamence than pushing a bad position. Also, with plenty of resistances and Calm Mind to boost Special Defense, Leftovers may be a good choice for an item.
Roserade:
Sleep Powder is definitely worth considering, since it gives you something for Roserade to do against virtually anyone (barring Insomnia and Lum Berry), and can make a nice opportunity for setup. Your ideal item from your choices is Black Sludge; Shell Bell's healing is inferior and Black Sludge will make your enemy think twice before using Trick (this is uncommon but it can REALLY screw you over if the user is holding something bad).
Salamence:
As said, ditch Fly. Outrage/Fire Blast/Earthquake/Dragon Dance Salamence is pretty much standard, but it is devastating nonetheless. You're basically running that with two substitutions for reliability over power. Dragon Claw over Outrage avoids leaving you locked in exchange for only 2/3 the power. IMHO Outrage is well worth it but it's up to you. Flamethrower over Fire Blast is accurate, but since you're investing in physical power and lack STAB, you really could use Fire Blast's extra strength. And 85% accuracy is better than most of the other power moves, so it is worth considering. I'd certainly understand if you don't want to risk a miss, but even with a weakness on your side, Flamethrower may take a good couple of hits to bring down some of the bulky Pokemon like Bronzong. For an item I'd go with an attack booster like Dragon Fang, Muscle Band, or if you can risk the recoil, Life Orb (common item in "standard" play, but I personally would not recommend it since Salamence is defensively valuable to your other team members, like Absol and Lucario).
Overall:
As mentioned earlier you could use some work-arounds for your Speed issues. Priority moves, Thunder Wave support, Choice Scarfing, that kind of thing. Your team is overall very straightforward attacking. The stat-ups are nice but some status annoyers could help you. You have no attacks of either Electric or Ice, both key offensive types, and an over-abundance of Dark/Ghost attacks, which besides their affect on Normal and Fighting are otherwise identical. You really do not need 5 of your 6 Pokemon to all be carrying attacks geared towards the same two types of opponents. On the plus side, Lucario and Salamence have some great synergy, being able to cover each other's weaknesses. In fact, you're pretty good on type variance as a whole, although something to resist Electric (to cover Feraligator) and/or Flying (to cover Roserade and Blaziken) attacks might be helpful.