> no way to prove
For a start, don't join Dad's company as VP when you're 22.
Luckily, they don't need to prove quality, because wealth is a good enough proxy indicator for almost everyone. If you're talking about proving to oneself, then they're on the same footing as everyone else.
> don't fuck up
Easy: don't do anything. Leave the money where it is. Take an annual allowance.
I think you're saying it's hard to have the self control to not meddle, to not insert oneself into the power nexus? I suppose. Hubris is human.
Frankly, that sounds depressing. Seen like that, people who were born to wealthy parents have no way to prove their own quality. They will always be suspected to be just lucky and riding the easy wave.
"then you can simply not fuck up"
There is nothing simple about that. I consider myself fairly smart and I fucked up royally several times in my life. It did not destroy me, I was able to put the pieces together, but none of the decisions seemed bad at that time, either to me or to people I consulted it with. There is a lot of traps out there.