Off-chain computation removes block verification costs from each transaction. How will miners get paid mining these transactions?
Costs are not being totally removed to my understanding but rather, it is minized due to the minimized block size which removes multiple block confirmations as is seen in on-chain computation networks
Your project came at the right time. Off-chain computation will reduce the issue of block size which will in turn eliminate the consistent forks aimed at creating more block size for existing blockchains.
Here is the most interesting part of the project. Off-chain computation solves the problems of on-chain computation at the moment especially that of block size.