Affiliate Payouts

I need to get my head around the export payments function in affiliates. Can the export payment file that is exported can it be uploaded directly to paypal?

I see a problem if I have hundreds or even more affiliates. Is there a way to select all and export? Same with select all as paid later after a mass pay to paypal?

Once paid, if I export payment again it should be zeroed correct? I am wondering If I can do daily payouts and if this system keeps tract of this.

Thank you