I have to say I've used Google checkout a couple times without issues. No errors or anything although it was a bit weird, so was Paypal when I first used it.

You cannot use a personal account to circumvent fees from business. If you have a business you need to send them al to your premier or business paypal account. Granted I'm not sure how they could catch you or what would be done if they did, just want to note its not technically allowed. You can check the Help/FAQ at papypal for more info.

I'm not sure how slim of a profit margin you are working with, but one way to get rid of the hassle and worry would be to increase your costs based on the fee associated with each. So if the $5 payment costs you .25 each time maybe bump it up to 5.20 or such. I've dealt with several places that either did this or refused credit card funded payments. Not sure howmany customers they lost however.

Offering multiple options can be a good thing, but if you don't want people using one over another you are setting yourself up for dissappointment by offering it at all. Murphy's law clearly states they will use whatever you least want more often than not.