I feel left out here because I consider selling any account illegal. People in the Digital Goods section sell their forum account, Amazon account, Phone Numbers, Email accounts, PayPal accounts and I don't know how many more accounts are being sold and bought.
I doubt its illegal. You might violate some companies terms of service though.
I can't get why is this allowed? I have just witnessed a "Trusted" member who sold his account and the buyer was indeed a scammer who tried scamming another member with the help of the Trusted account. I don't know how many times has it happened here.
Trading bitcointalk.org accounts is allowed because a ban of those trades is considered unenforcable. It would be impossible for mods to enforce the rule, because sales would just happen elsewhere. It is however discouraged for the reason you stated. It allows someone to buy a trust rating.
Selling Trusted PayPal accounts is the biggest blunder as the buyer can use it for money laundering and illegal things while the seller will be blamed for those deeds and it is a CRIME.
Selling a "trusted" paypal account is certainly not a crime. Many things are used for money laundering and illegal things. I hear knifes are dangerous killing instruments, yet people use them daily to butter their bread. Dont jump to conclusions, I cant speak for paypal, but most bitcointalk account sales probably happen for paid signatures.