To add to what I previously stated, why so strict choice? That only happens in movies when a hero need to choose who's going to live and who's going to die (both are his friends/relatives)
I doubt that any person can work 80-70 hours per day, only if it gives you joy. Otherwise you might get into some health issues/whatever and those 100k become 200k or who knows what. From what I've seen/read a person can't actively work more than 6-8 hours. Other time is spend for some shit like browsing, social etc. So why say no for friends/relatives anyway?
As for the rent, Idk, but IMO living apart from your dad/mod not only motivates more (you gotta pay for the rent etc), but it is also a sort of 'gateway' into adult life. For example, when I made my first money I moved to a cheap place and then when my income increased I moved to a better apartment. You can do the same.