Is this team meant for Battle Spot, or Pokemon Showdown? I'll assume the former, since Mega Kangaskhan is an Uber in Showdown! play.
Venusaur needs its Mega Stone to function well because Thick Fat eliminates 2 of its weaknesses and Mega Venusaur is bulkier and stronger than regular Venusaur. You can get away with using 2 Mega Pokemon in Battle Spot teams; you just pick the one that suits the team you're facing:
-Giga Drain
-Sludge Bomb
-Leech Seed/Sleep Powder/Earthquake
-Synthesis
Nature: Bold/Relaxed
EVs: 252 HP/240 Def/16 Spe
Item: Venusaurite
or
-Giga Drain
-Sludge Bomb
-Hidden Power (Fire)/Leech Seed/Sleep Powder
-Synthesis
Nature: Modest
EVs: 236 HP/252 SAtk/4 SDef/20 Spe
Item: Venusaurite
Flash Fire or even Infiltrator are the preferred abilities on Chandelure. The former gives it an immunity to Fire moves and powers up Chandelure's own Fire STAB, while the latter lets Chandelure ignore Substitute, Reflect and Light Screen when attacking. I'd use Choice Scarf to compensate for Chandelure's so-so Speed; also, Fire Blast is preferred over Flamethrower for the greater power. Its accuracy is still acceptable. Also, don't bother with Delphox; there are too many Fire Pokemon that outclass it, even Chandelure. Froslass is only good for Spikes leads, but it's not really effective in Battle Spot formats:
-Fire Blast
-Shadow Ball
-Hidden Power (Ice/Fighting)
-Trick/Energy Ball
Nature: Modest/Timid
EVs: 4 Def/252 SAtk/252 Spe
Item: Choice Scarf
Ability: Flash Fire/Infiltrator
I'd just use paraflinch Togekiss if I were you; I feel it's doing a bit too much at once:
-Thunder Wave
-Air Slash
-Dazzling Gleam/Aura Sphere/Flamethrower/Defog/Heal Bell
-Roost
Nature: Calm/Bold
EVs: 248 HP/8 Def/252 SDef or 248 HP/252 Def/8 SDef
Item: Leftovers
Ability: Serene Grace
Continued from a previous point, you should give Assault Vest Goodra a try:
-Draco Meteor/Dragon Pulse
-Fire Blast
-Sludge Bomb/Thunderbolt
-Earthquake/Muddy Water
Nature: Quiet/Modest
EVs: 240 HP/252 SAtk/16 Spe
Item: Assault Vest
Ability: Sap Sipper/Gooey