It is certainly a gray area but is not explicitly barred by the T&Cs. IANAL but I would think they would have to explicitly close that loophole before being justified in nuking someone's account. Mileage running is also a gray area that exploits a loophole in the T&Cs of airline programs, but nobody's account gets nuked for doing that (except possibly for Delta).

Actually, IIRC the additional language does not refer to the T&Cs specifically but states that providing false information is grounds for termination. However, this is because providing false information is in effect fraudulently obtaining a reward (by filling out a survey for which you are not qualified). Despite the gray area, there is no overt fraud in gifting an (already earned!) reward to a friend or family member, as long as it is a true gift and not a sale/trade.

Sure, but I believe e-Rewards does not check the transaction history of the airline account, only of the e-Rewards account. Their system explicitly denies multiple transfers in a year anyway, and as evidenced by other threads here, changing the name on the e-Rewards account does not work to allow multiple redemptions - the system recognizes that the specific account (regardless of what name is on it) has redeemed in the past year and disallows multiple redemptions. While the e-Rewards account name and the airline account name must match (hence my original question of changing the name), I don't believe e-Rewards checks the transaction history of the destination airline account (the airline would need to provide access to that history and I don't believe that happens).

In any case, while I genuinely appreciate the concern, I am not trying to justify whether or not this is a good idea... I am sure there are risks involved although this is not explicitly prohibited by the T&Cs (although I agree it is a "gray area"). My question was whether other people who have done this have experienced problems and/or what their procedures were.