Well to be honest with you, hax is simply part of the game. Yes, I'll admit that it can be extremely frustrating at times when an opponent that you know does not have the same caliber of skill as you do wins with luck, although it just goes that way sometimes. I think that there is a way to minimize hax though. If you're playing a game and you make sure that you think through your moves at every turn, then this is a way to minimize hax. If you do not play risky when it is unecessary, then hax is minimized. For example, say that you have a dd dragonite against your opponent's standard tentacruel with a set of scald / toxic spikes / protect / rapid spin. Something that a lot of people may do is simply let dragonite take scald thinking "oh it's only a 30% chance, I won't get burned," and your opponent's scald burns the first time around. If dragonite happens to be crippled, and you need it to win the game, then it is honestly your own fault if that happened.
The only times that I would "rely" on hax is in a situation where if I don't make a certain move, then I lose the match. For example, if I have a moxie scarf salamence as my last pkmn while my opponent has a half health choice banded terrakion, rotom-w, and hydregion, then I need to "rely" on outrage to win me the game. Another example would be if I have a rain based volcarona with little health left using the moves substitute / hurricane / bug buzz / quiver dance against my opponent's specially defensive jirachi, I would use hurricane in an attempt to get confusion hax rather than going for a critical hit with bug buzz. Although these examples are pretty situational, I think that it still proves my point. Hax is part of the game, and if you want to play this game competitively, then you need to deal with that fact and use it to your full advantage. On the subject of how much I get "haxed" I would say that I'm unlucky a fair bit of the time. Although there are sometimes where I have my fair share of luck so I can't say that I'm terribly unlucky most of the time.