Well, I decided I had to bite the bullet.
As previously mentioned, I had hit my PayPal account limit last month, and had to deny a couple of payments. I was thinking maybe that would be a fluke, and never be a problem again.
Then I noticed that I'd gotten in excess of $65 in payments within 24 hours of the limit resetting, and I have a limit of $500 for the whole month.
Obviously, this was not going to work.
So, I have created a new PayPal account, which accepts credit cards, and I'll just have to deal with the fees incurred by each payment. Better to lost $0.30 + 2.9% each time than to lose entire sales and customers due to the complexity of sending funds to another account (many people are surprisingly unable to handle anything other than "Click on Pay Now"). I suspect some potential customers have been turned away by my warnings of having to wait for instructions on how to pay by credit card.
Now I have to figure out if there's an easy way to get rid of the "For credit card orders..." message in each and every one of my store listings. Ugh.