The duration of receiving mining rewards depends on your willingness to cover the daily hosting fee. As long as you continue to pay for the electricity your miner consumes, you can expect to receive mining rewards.

The hash rate for your miner remains stable over time, meaning that if you purchase a miner with a certain hash rate, such as 100 TH/s, it will still have the same hash rate a year from now. However, it's important to note that factors such as the BTC price, network difficulty, and rewards per block can affect the overall profitability of mining.