The safest way to use Paypal:
Never, never, ever under any circumstances let money sit in the account. Not unless you want to run the risk of saying "bye bye" to it forever.
I have used PayPal for years, and have never had either my business or my personal accounts frozen. However, I've always kept it foremost in my mind that they are NOT a bank. Funds left with them are not FDIC insured and protected the way my business and personal bank accounts' funds are. The money left in PayPal's care also earns interest for PayPal / Ebay, instead of earning money for me.
While I can understand their business model, I'm not going to encourage it more than I already do by using the business account, which does take a flat fee and a percentage (smaller than most merchant accounts or processors, but still...that's my money, darn it.)
Scribehost's clients seem to be an even mix of Paypal and credit / debit card, with one client who occasionally pays via money order. The business hosting arm, though, sees more credit card payments.