Yes it is safe. Since you asked very generally, I will explain in abit and hope that works for you.
Money goes into your PayPal account once you have everything verified. It is pretty safe and all you need to do is to hit the minimum payout. This is done monthly.
If you talking about how much HP earning can be counted, it really depends on your luck I would say. Yes, it gives us good earning but again it boils down to 'market' factors. For example, I am earning lesser daily now compared to 3 months back.
So yes, if you want to earn more money with HP, try writing more evergreen hubs :)
Hope this helps!