This team needs a lot of fixing. Since this is OU, many of your Pokemon cannot function properly and are also outclassed easily. Get ready for a giant wall of text...
Politoed
You lack a Special Wall, which is one of the things Politoed does well. To satisfy this, we'll turn Politoed into a Special Wall, as you have a Special Attack in Eelektross as well.
Politoed @ Leftovers
Trait: Drizzle
EVs: 252 HP / 16 SAtk / 240 SDef
Calm Nature (+SDef, -Atk)
- Surf/Hydro Pump
- Toxic
- Protect
- Ice Beam
A common ToxicStall Politoed. Indroduces Rain for major team support, and serves as a Special Wall. Surf and Hydro Pump are both STAB, and with little investment in SAtk can deal decent damage to anything that doesn't resist it. Toxic and Protect either stall off your opposition (while restoring health with Leftovers) or forcing switches. Ice Beam is coverage.
Lapras
Needs replacing.
It doesn't function properly in OU, and when there's Ferrothorn which outclasses it's walling ability in every way, Lapras' replacement isn't too hard. I'm going to suggest a standard Mixed Wall Ferrothorn.
Ferrothorn @ Rocky Helmet
Trait: Iron Barbs
EVs: 252 HP / 88 Def / 168 SDef
Relaxed Nature (+Def, -Spd)
- Spikes/Stealth Rock
- Leech Seed
- Power Whip
- Thunder Wave/Gyro Ball
My everyday Ferro that Rain teams love support from. Taking your Electric and Grass weaknesses easily, Ferro keeps your synergy up to date. Spikes and Stealth Rock are your hazards, and doesn't matter too much with which you choose. Leech Seed saps your opponent's HP, while Iron Barbs and Rocky Helmet deal extra damage to the opponent with every contact move, means Ferro can sponge an attack and cause some damage back to the opponent. Power Whip is there so you aren't complete Taunt bait, and is STAB. Thunder Wave and Gyro Ball are both great moves, but are a choice. Gyro Ball is more STAB, but it doesn't give too much more coverage than what Power Whip already gives. Thunder Wave is more tricks for walling, and cripples speedy Pokemon, in a way serving as a patch to Ferro's atrocious Speed.
However, if you want to keep Lapras, your set needs MAJOR fixing. Focus Sash on a Wall makes absolutely no sense. Give it Leftovers. ResTalk looks like a viable option with your current set, so replace your Sub with Sleep Talk. Thunder's tempting 100% accuracy in Rain in great, but considering Lapras' lower offensive stats and the fact that it serves no STAB means it is a waste of a moveslot, and Lapras it therefore walled. Replace it with Scald, which if the opponent is burned, helps with your physical defence, which allows more investment in your Special bulk. Use this EV spread: 252 HP / 76 Def / 180 SDef.
Armaldo
Drizzle + Swift Swim is banned in OU. Which means this thing is pretty much prone to revenge killing, which is also one of the things your team needs; a Scarfer. Most of your team is relatively slow, and a speedy Pokemon seems like an important part of this team. I'm going to suggest thy epic pony, Keldeo-R. A standard Smogon set below:
Keldeo-Resolute @ Choice Scarf
Trait: Justified
EVs: 4 HP / 252 SAtk / 252 Spd
Timid Nature (+Spd, -Atk)
- Hydro Pump
- Secret Sword
- Hidden Power Ice
- Surf
Revenge killer. Works pretty obviously. Hydro Pump is STAB, and hit pretty hard coming off that 129 SAtk Base Stat. Secret Sword is also STAB, and allows Keldeo to hit Physically whilst still abusing it's large Special Attack. Keldeo's bad Choiced movepool forces Hidden Power Ice, mostly due to it's lack of Ice Beam. Allows it to deal with +1 boosted Dragons, who otherwise cause your team a problem in terms of coverage. Keldeo's movepool strikes again, leaving the less powerful Surf an option. Weaker STAB than Hydro Pump, but it's reliability is a gift.
Dragonite
I haven't passed the character limit yet? /facepalm
OK, no offence but that Dragonite set is terrible. You have two options here: a mixed attack, or a physical sweeper. Since this is rain, Hurricane mixed attacker is a good option, but Toxicroak as your only physical attacker isn't a good look. So for that very reason, I'm suggesting an improvment on your current Physical Dragonite. And I'm going to whack a Choice Band on.
Dragonite @ Choice Band
Trait: Multiscale
EVs: 4 HP / 252 Atk / 252 Spd
Adamant Nature (+Atk, -SAtk)
- Outrage
- ExtremeSpeed
- Waterfall
- Earthquake
More material from Smogon. Outrage is STAB, and hits incredibly hard with Dragonite's sky-high Attack stat. ExtremeSpeed is lovely priority, with 80 Base Power which means Dragonite's improvable Speed is less of a problem. Waterfall is extra rain power and serves as coverage. Earthquake is classic, but serves a more critical purpose in the set, allowing the ever-so-problematic Steel types a check. Fire Punch is preferred in this slot, but it next to worthless with Rain decreasing it's power.
Toxicroak
Needs some fixing.
I don't know what you're doing with your EVs. Trying to wall with Toxicroak? Nooooo.
I'm going to suggest a Swords Dance set. Since you don't have det Dragon Dance on Dragonite, I wanna get some setting up in here. Blame it on my logic.
Toxicroak @ Life Orb
Trait: Dry Skin
EVs: 252 Atk / 252 Spd / 4 HP
Adamant Nature (+Atk, -SAtk)
- Poison Jab/Ice Punch
- Sucker Punch
- Drain Punch
- Swords Dance
Fixing up your set here and there. Pretty straightforward again. Poison Jab is STAB and has a nice chance to poison, though Ice Punch gives it something to hit Dragons and other lurking threats such as Gliscor. Sucker Punch takes prediction but is nice priority. Drain Punch is more STAB, with a neat side effect. Swords Dance is the move that allows the set to hit hard, rocketing Toxicroak's Attack up high.
Eelektross
Has the potential to shine, but hasn't an impressive movepool or offensive total stats, unfortunately. Easily outclassed by Thundurus-T, who shall serve as your Electric type here.
Thundurus-T @ Life Orb
Trait: Volt Absorb
EVs: 252 Atk / 252 Spd / 4 HP
Modest Nature (+SAtk, -Atk)
- Thunder
- Hidden Power Ice
- Nasty Plot/Agility
- Focus Blast
*Thunder is STAB, full accuracy in Rain. Hidden Power Ice is again my choice of coverage, allowing you to hit things like Gliscor and Dragons who like to suck up your Thunder. Nasty Plot and Agility are both good setup moves, use either to your fullest advantage. Focus Blast is coverage, and means trouble to things like Blissey, Tyranitar, Ferrothorn and other things that wall Thundurus.*
Good luck with your team.