So, for example, one computer can only output 1 GH/s mining hash rate, and if they want to increase it legally, they have to add more computers. Is this what you're trying to say?

If this is the case, I can see a lot of people using other clients or just straight up forking the network if they think it is worth the cost. Whether it is hackable or not is just speculative at this point since there is no code to scrutinize. Even if it is unhackable though, what I mentioned previously is still likely to happen. What is the purpose of this limitation btw? To prevent centralization or something else? I don't see how it works if the former is the purpose. CMIIW.