1. I don't know for that website, but a quick search told that it should be legit. They have a not-really-updated
announcement also on this forum.
2. If you edited eth_pool.bat like in the video, that's pool mining. And as I said, in solo mining you'll probably get nothing.
3. Last time I've been mining it was not recommended to mine to an exchange address, what the video recommends (Binance); you may be better with your own address.
4. As idea, you may also look for pool that automatically exchanges the mined ETH into BTC for you.
5. Make sure you understand that at the end of the month your electricity bill will be higher and these earnings should also cover that.
6. I don't know if the earned 4$/day is OK, but as I said, you should ask these things the actual miners in the actual mining subforum.
Dear actually I mining nicehash.i will attach images.the thing is earlier in nicehash site I earn 0.00012245 btc per day.but that time I got low dollar rate. Because that time Bitcoin price lower than now.but now I can earn 0.00010892 btc per day.but now I got higher $ rate. Because btc up now. I think nicehash cheating. That’s why I need to know anyother solution like direct mining.i don’t want Btc mining.anyother coin also ok. Can you guys recommend anyother site or software for me.