Which payment processors offers irrevocable and instant transactions? I'm looking for alternatives to Paypal. I'm already aware of Skrill (Moneybookers).
There are lot of alternative. Skrill is difficult to verify for some countries due to different currency. You can try payza.
Pretty much nothing. Most buyers will not make a purchase without some protection. Western union would be another one, but good luck getting any buyer to use one of these.