Some very simple, basic answers for your questions you can read the full topic HERE
No one can tell you !
Always going to be a 2 group of ppl who telling you it's ok go for it , or dont bc you just wasting ur money and time !
You have to make a decision for yourself !
Do your own research !
No one can tell you for sure what's going to happen with cryptocurrency !
No one can tell you it's going to be profitable for you or not !
No one can tell you how much profit you going to be able to make ! ( if you can make any at all )
No one can tell you the ROI ( return of investment) time !
No one can tell you what is the best coin to mine !
No one can tell you what is the most profitable coin to mine! Coins profitability always changing, what is best to mine today, maybe going to be the worst to mine tomorrow !
None of those calculators you are seeing on the web can tell you what's coming tomorrow , months later or 6 months later !
Those calculators telling you about today , at that moment when you typing in your information !
None of those online calculators calculating pool luck !
None of those online calculators calculating your stale/rejected or invalid shares !
None of those online calculators able to predict difficulty growth !
None of those online calculators can predict what would be the coin/$ exchanges rates a minutes later, a hour later, tomorrow, next week, months later, 6 months later or a year later !
It's little bit of gambling , you must to decide you want to play on the lottery or not
YES some of us got lucky , made some money with mining
YES some of us got unlucky , lost some money , bc when price started to fall , sold they coins , miners...
! INVEST ONLY WHAT YOU'RE WILLING AND ABLE TO LOSE !
! INVEST WITH THE UNDERSTANDING , THAT YOU COULD LOSE EVERYTHING !