1.- How will income taxes be paid? I intend to use the "Collected by itch.io & paid later". These are paid by itch.io and i get the final earnings only (only the royalties)? or do i have to pay taxes apart from the taxes withheld?  

2.- Also...what does ITIN have to do in all this? Is it mandatory?

3.- Are Income Taxes mandatory for foregin non-US sellers (well, rather, are these already in the tax withlehd?)

Some useful information here

-I live in Honduras, non-US citizen, alien

-Honduras and US have no treaty, so whether i apply for it or no, I know I still have the 30% withheld.

-I already filed a W8BEN-I form (edit)

Sorry the way its redacted lol, I am new at the tax thing

Thanks in advance!