No, twinking is not cheating. The rules of the game do not forbid the transfer (and even encourage) trading items between characters. My two cents: Play the game however you like that makes you happy within the rules.
If however you were to join up with a group that had all agreed upon some set of rules, like "IronMan", then twinking might be cheating within that agreed group. Non-twinked is a much higher challenge to play and win, so I say more power to you, if that is how you like to play.
Personally, if a Bartucs drops for my high level amazon, I will transfer it to my assassin rather than sell it to Larz... There are some sets items and other items in the game that are so rare (like a good Rare item), that you would never sell or trade away just because they dropped for the wrong character type. I agree with WarBlade, though, most gear transfers that I make are on players that have already beaten Hell Baal. As my characters progress through levels, they grow out of their gear. So what do you do with that Um'd Duriels shell?
If however you were to join up with a group that had all agreed upon some set of rules, like "IronMan", then twinking might be cheating within that agreed group. Non-twinked is a much higher challenge to play and win, so I say more power to you, if that is how you like to play.
Personally, if a Bartucs drops for my high level amazon, I will transfer it to my assassin rather than sell it to Larz... There are some sets items and other items in the game that are so rare (like a good Rare item), that you would never sell or trade away just because they dropped for the wrong character type. I agree with WarBlade, though, most gear transfers that I make are on players that have already beaten Hell Baal. As my characters progress through levels, they grow out of their gear. So what do you do with that Um'd Duriels shell?