Guide to breeding pokemon with Perfect or near-Perfect IVs ver 1.1
First of all, breeding a Ditto with a Krilia should give you Ralts (Krilia's first evolutive stage) eggs
Note on 2: (that means they are the 31 IV stats?) Be sure that he says those stats "can't be beat"; as long as you've caught the pokemon on the Friend Safari they should be OK.
QUESTION 1: For competitive battle? Yes, it matters 
QUESTION 2: For competitive battle? Yes, it matters 
4 and QUESTION 3: It's random. When you breed pokemon 3 random stats (5 if any parent is holding a Destiny Knot) will be passed from a parent. Which stats? It's random. Whose parent are the stats passed? It's random too on each stat. You'll need to hatch the eggs and go to the guy in Kiloude again to have their IVs checked.
 The nature increases a stat on 10% and decreases another stat in 10% (if the stat increased and decreases is the same there's no change). In the Summary screen you can see the increased stat sightly in red and the decreased stat in sightly blue.
Since competitive Pokemon rarely run with both Physical attacks (damage calculated by Attack stat) and special attacks (damage calculated by Sp. Attack stat) in the same set you can usually decrease the unused Atk/Sp. Atk stat to have a small boost in abother stat you'll actually use.
 IVs matter at competitive scene because they mean a 32 point difference on each stat at level 100, free of charge and even before
Where can I buy a sarcasm detector? Mine is broken
3DS FC: 3411-1630-3825 ~ Pokemon X Safari. Beautifly, Heracross, Butterfree ~ TSV: 377 ~ 896 - 1443