Its better to cashout your first deposit after winning some good amount of money. And keep playing with what you have won so that even when you will loss all you will only loss your winning.
I will rather cashout all my deposit + winning if I will make some good profit with few rolls and try to limit my greed for more profit.
True, safeguarding your profit on the winnings can make you keep going on the long run, on the other side only few have the patience to now use that profit to bet more especially in live games but it is always better to think that not everyone is winning and what you have won must be into you and yours alone before you lose it all again in the next bet.
Not, of course. Do not play with your profit because you can use it instead in other income generating activities. There is no assurance that you will earn if you use your profit in gambling. It is very risky. It is about win or lose.
They already know the consequences in gambling so there is no need to remind it to them, what matter now is how they will handle the times when they are in a streak of win and to know the limitation when they are losing. Handling the situation on both sides can keep your loss less, and your win, more.