For your account not to be limited by Paypal , You MUST obey these following rules :
1. Don't delay in issuing a refund when a customer insists on it. One thing is that Paypal doesn't protect you if you are selling digital products. Since they don't know you too well or your behaviour, once a customer reports about a delay in effecting a refund they will limit your account because they usually want to play safe. You know that your account is with them and you don't have absolute control over it.
2. Don't add your Paypal account to Net work marketing or Multi-level marketing (MLM) site. It is against their terms of service (TOS). If you do this , the next thing you will see is your account is limited.
3. Don't concentrate all your money in one Paypal account, if you have more than one . If you have one Paypal account, you can have several Paypal accounts attached to that one Paypal account as e-mails that are verified. And you just add several e-mail addresses. But I will advise that if you have more than one Paypal account when you make money with one , send it to another one as a reserved account incase they limit your account.The reason is that onces they limit your account, your money is tied there.
4. Don't supply a different e-mail address as your account. The e-mail address which you used in opening a Papal is your account. So anytime you are asked your Paypal account, add your e-mail adress and not any other.