How long can I expect to receive mining rewards for? Does the hash rate decrease over time?

We provide a stable hash rate for as long as you cover the daily hosting fee. For example, you buy a 100 TH/s miner today. A year from now, you will still have 100 TH/s. 

What varies? The BTC price, Network Difficulty and rewards per block (next halving expected in May 2024).