Honestly, I never could get a handle on EV training. As for natures, I picked the best recommended natures for each of the Pokemon. I won't know abilities until I actually start catching the Pokemon.
Also, it would be helpful if alternatives could be suggested to make my team more able to fight competitively.
I don't know how it is on ORAS as I'm still waiting for paypal to LET ME BUY IT PLEASE I NEED IT. Well as I was saying, I don't know how it is on ORAS but in XY with the supertraining is really easy to check the EVs and to EV train your pokes.
The best way to EV train your pokes is as easy as this:
.Clean their EVs (unless they are just caught), you can do this using a reset bag on them (supertraining) or using EV reducing berries on them until it says the stat can't go lower.
.Get a pokemon with pokerus (I can trade you one).
.Get the power items (you usually are allowed to get them after beating the game), there is a power item for each stat.
.Equip your pokemon with the power item.
.Look up on the internets where you should look for a pokemon that will give you the EV you want.
.If there're hordes, you beat 6 hordes of that pokemon and you are done with that stat, if there are not hordes, you will have to beat the pokemon again and again.
.Done, you have your trained pokemon ready to kick ass.
If you want to play competitively, you NEED EV training, and natures, and sometimes the ability will matter too.
Also, there might be differences depending on if you want to play Singles, Doubles, Etc.
Now, let's see your team...
I would run scald instaed of hydro pump on Milotic, I see it more like a defensive pokemon. It has a nice special defense, and you can lower the opponent attack if you burn it with scald. Also, if you want to take a defensive approach on Milotic, you could use Recover on it.
False Swipe on absol? I expect that's just to catch pokemon because it's useless on competitive.
Heracross will be your mega evo, right? because if not I might change the 2-5 hits attacks for another thing.
Rhyperior... I like using rock polish on it to outsped stuff and wreck it. And brave nature? why would you want to lower its speed instead of its special attack if your team doesn't carry trick room?
About blaziken, I think stone edge is better than thunder punch, it lets you hit flying types for more damage (even though it's less accurate), high jump kick would do more damage than thunder punch to water types anyways.