Probably it is not so easy. Try to find something here in the forum, some samples - https://bitcointalk.org/index.php?topic=5051840.0, https://bitcointalk.org/index.php?topic=3337326.0. One of best site is this too - https://www.privacytools.io/.

If you have small amount of Bitcoins, like 0.05 BTC you can trust them. But if you have more Bitcoins, hardware wallet would be much better option. Look also here https://bitcointalk.org/index.php?board=222.0.

Yes, plus you can save on many costs too. And for happy family life this is best, I think. Due to COVID many people already work from home, so in future online business will go up.

They will pay repayment, Nicehash is quite large company, in any case you can contact staff via Facebook. Look here https://www.nicehash.com/blog/post/nicehash-keeps-the-promise-and-will-fully-reimburse-its-users