Well, I'm going to answer your RMT. Firstly, although your team has good type synergy, the EV spreads are sort of strange. As a general rule, if you want to maximise your pokemon's ability to take hits, it's EVs should be split between HP and defense stats. For example, giving your Gardevoir max HP, then defense evs split evenly, would make it much more bulky.
Right, let's move on to the team.
Firstly, Ampharos. A better EV spread would be 252 HP / 252 SAtk / 4 Def , with a Modest nature. Take out Signal Beam and replace it with Focus Blast. Thunder Wave is an okay option I guess, although if you're crazy about the paralysis, you could always replace Thunderbolt for Discharge and give him a team supporting move like Heal Bell. Lastly, a Magnet? Seriously? It only gives you a small boost to one move. Give him Leftovers or Life Orb, it's up to you.
Next, we have Golurk. A Brave Nature is not the wisest idea - make him Adamant. Although it is awesome that he can use Fly, it's not a great move as the opponent can switch to something that will easily take it. For Golurk you have two options: Give him Substitute and Focus Punch abusing Iron Fist, or use No Guard with DynamicPunch, and a filler move such as Stone Edge.
Regice makes a good special wall, but not a mono-attacker. Also, Earthquake and Hammer Arm aren't going to do much coming off base 50 attack. A standard set for him would be Regice @ Chesto Berry, 252 HP / 252 SAtk / 4 Def , with Toxic/Thunder Wave, Ice Beam, Thunderbolt, and Rest. This works well, as he has BoltBeam coverage and outstanding special bulk.
Gardevoir looks pretty good, but replace Destiny Bond with Focus Blast, give her a Life Orb, max speed, and a Timid nature.
Now onto Samurott. A mixed set is not great with him, and also, why use X-Scissor when he gets Megahorn? As you have quite a few Special Attacking pokemon on your team, i'll suggest a Swords Dance Sweeper:
Samurott @ Life Orb
EVs: 252 Atk / 252 Spd / 4 HP
Jolly Nature (+Spd, -SAtk)
- Swords Dance
- Waterfall
- Megahorn
- Aqua Jet
Finally, Serperior. Well, I presume Leaf Storm will be used with Contrary. HP Fire, Ice, or Rock are all better options than Steel. Twister and Hyper Beam are terrible moves, although you may be wanting to use them in some sort of 'humiliation defeat'. Unfortunately, he doesn't have many other options. I suggest a SubSeed set, with max Spd and SAtk, Timid nature, Leftovers, and Substitute, Leech Seed, Giga Drain and HP Fire.