Couple of questions

Dear support,
thanks in advance for your attention on this matter.

1. I would like to add my own payment gateway, I would like to make this as a donation website so customer get charge right after they commit. May I know if there is any documentation for me to refer, how can I implement this feature on this theme?
2. May I have the sample code for the demo homepage? I would like to do something similar but my one click install doesn’t include demo homepage
3. May I know how can I add extra currency into the project page? Currency for my country is missing from the default option.

Thanks