First, you need some WAVES. There are several ways to purchase cryptocurrencies. Caveman Lab does not make instructions on how to buy cryptocurrencies. Once you have some WAVES in your wallet, you can lease to the pool (3P3aayN8kE6gXo7jSki7WUJHdTAF4X4S9xA) by reading this guide.
By leasing to the Caveman Lab WAVES Node leasing pool, you will get 100% of the rewards generated by your leased amount. Besides, you will also get CLMT each time, so it is more than 100%.
Once per week for now. The payout time is at Sunday midnight (UTC).
No, the leased amount will take effect after 1,000 blocks (roughly 16 hours 40 minutes). You can check the leasing pool status. The 'effective balance' will reflect your amount immediately, but the 'generating balance' which is used for mining will not reflect this amount until 1,000 blocks later.
No, the canceled leases will not be paid. Active leasers will share any rewards generated by canceled leases in that period of time. The Lab would encourage long term leasing. However, if you have to cancel your lease, it is recommended to cancel after a payout.