I've received a notice that I couldn't add a credit card because the number was already on my wife's account. Not sure if the same is true for checking accounts, but I'd imagine so.

They don't allow that. My wife tried to add her checking account to a business-related paypal account, but it was already on her personal account so they didn't let her connect it.

What you should do is unconnect it. The very last thing you want to do is to give paypal unfettered access to your checking account.

Why would you tie your paypal account to a bank account?

To get money out. (I don't have mine tied, because I don't receive any money via paypal, and probably never will because of all of the horror stories.)

Anyway, you can easily exchange "bank account" with "credit card" - and it seems that they don't allow that sort of thing, based on the other comments in this thread.

Yes, but they are also quick disable an account with suspicious activity. Some would say too quick.

You really only need the account for about five minutes, in order to register your spambot.