The merchant processor does not want chargebacks either, so when a chargeback is initiated you get a document describing the chargeback reason, and they generally ask the card holder to have some proof that they attempted to contact you to rectify the issue but did not get satisfaction.
So, run your business. Do a good job, concentrate on your company. Chargebacks won't be an issue unless you re doing something horribly wrong.
If you have too high of a chargeback ratio, you will get cancelled. I think you might be worrying about something that you don't need to worry about. As long as you are providing a real service/product and not out to rip people off, you will be fine.
We've had around 500 customers and not a single customer has requested a refund yet.
Note, when a person requests a charge back through Pal Pal, Pay Pal will ask them to prove their side, and I don't remember the person ever doing it successfully. The successful people initiate the charge back via their credit card company and Pay Pal always accepts those and charges me.
if it is a physical product, just keep proof of sending the order on file such that you can prove to paypal that you've sent the goods.
if it is a digital product I recommend you get a specific service to deliver the product and handle the transaction, such as shareit, clickbank, digital river, ... they know what to do with chargeback for digital products.