In order to activate mining, the node needs not less than 1000 LTO (for testnet we can always provide you with that, do not hesitate to contact us).
More revenue if you have enough people leasing to you and payout is not 100%. Also you can provide services on LTO Network with your node. Running a node might be profitable later on but it's not at the moment. If it is it's only marginal.
Yes, there are payout scripts that are used by node owners to pay leasers. These can also be used/adjusted to do other automateded transfers, e.g., LTOLPoSDistributor.
Please check Data transaction article.