Question

Name: Serperior
Nature: Adamant
Attacks:
1. Leaf Blade
2. Strength
3. Toxic
4. Coil
Item: ?

Emboar
Adamant
1. Flare Blitz
2. Wild Charge
3. Earthquake
4. Bulk Up
Item: ?

Samurott
Adamant
1. Mega Horn
2. Waterfall
3. Slash
4. Swords Dance
Item: ?

Haxorus
Adamant
1. Outrage
2. Brick Break
3. Earthquake
4. Swords Dance
Item: ?

Answer 1

I think you have a well rounded team. Haxorus knows Brick Breack and that is GREAT for coverage against ice. Emboar also knows wild charge and that is good coverage for water. I would suggest maybe a dragon fang for Haxorus, a Characoal for Emboar, a Mystic Water for Samurott, and a Miracle Seed for Serperior.

Answer 2

You team all round good. It's good that Samurott has mega horn cos it covers grass but you should teach it x-sciczor. It's less powerful has more PP. You also might wanna teach it dig for when versing electric types. For Emboar if your using earthquake to cover rock types teach it brick break instead of earthquake. Earthquake is more powerful and has less PP and its all pokemon on the feild but brick break is a fighting type move which means its going to do extra damage and it knocks out reflects and light screens. Give haxorus a persim berry even though its used once you can prevent the confusion from outrage. With seperior you might wan't teach it aerial ace or iron tail to cover weakness (iron tail - ice and aerial ace - bug) hope this helps

Answer 3

Ummmm...... You Need a Special Pokemon.
If this is an all Phsycial Team thats fine but for some Special Pokemon(Your Team is Great Currently), I'd Reccomend:

Chandelure@Choice Scarf
Nature: Timid
Moveset:
Energy Ball
Psychic/HP[Ice]
Flamethrower
Shadow Ball

And:
Thundurus@Leftovers
Thudnerbolt
Nasty Plot
Dark Pulse
Grass Knot/Focus Blast