Indeed. Those cheating problems that you mentioned are well known issues same as GTA Online. They're very annoying, and really loud on voice chat.
Because of this problem, many people used to make their private lobby session but I think it has patched ver6 recently, but it still works shortly something like 15-20 minutes.
Btw that red jacket killed my horse. I was so mad

I didn't want to buy Rockstar's game because of the rumors of GTA5's innocent ban, but watching the play video keeps making me want to buy it.
By the way, isn't it too cruel to pour oil and burn it with fire....?! ;_;