Q1. Definitely. Most immediately, in order to stake CTSI and participate in CTSI Reserve Mining, you will need to run your own node. We offer a bunch of convenient ways to do this and have written a thorough guide here: https://medium.com/cartesi/running-a-node-and-staking-42523863970e
You can also find other options on the open source repo, such as setting it up in Heroku, a cloud app provider: https://github.com/cartesi/noether
For any questions on running your own node or help with setup, you can join our Discord channel: https://discordapp.com/invite/Pt2NrnS our entire development team is there to help out.
Q2. That is correct, as we are a layer-2 system and are bootstrapping the future network for Noether, our highly optimized data availability sidechain for temporary storage, whenever you produce a block with your Node, you will have to pay an Ethereum transaction fee, this will however also grant you a reward in CTSI (2,900 for the next 6 months), which more than covers the cost of the ETH transaction fee. You only need enough ETH to cover a transaction fee for each block produced – so the life of the node is up to you.