I send people GG after a battle, I try not to get pissed about hax cause i usually do/say something when i get pissed and i try not to offend people.

I say GG and don't get pissed off about hax.

Once when one of my opponents asked about my team, I gave him full details of it, only to have him copy it and challenge me.

I 6-0ed him and pointed out a couple flaws, like how you're not supposed to lead with Ditto. He did, and his Ditto, which Transformed into Dragonite (I play DW OU) got burned by Suicune, and yet he stayed in anyway. Not to mention the fact that he switched Latios into Dragonite as I DD'ed up.

The subsequent battle he got 6-0ed by a SD Scizor, a flaw of my team at that point. He pointed this out, and I learned from it, to create a DW OU team that would later peak at 1342 rating.

tl;dr: Be nice to your opponents, they might do something for you afterwards.