You can’t simulate the earnings because you can’t predict the future price of the coin you are mining. And even if you say hedged your position by selling a futures contract, kind of like agriculture farmers do, you cannot calculate what the difficulty will be. Difficulty is what controls the supply of the coin, the more people that mine the higher the difficulty will be. If the difficulty doubles it means twice as many people are mining and your profits will be exactly half.

Once an ASIC becomes obsolete it’s basically a door stop. You can take some parts like fans and PSUs and reuse those and you can recycle the metal parts but that’s pretty much it. You cannot make it more efficient or mine some other coin.