I did the math on the stock market, and it is kind of useless profit-wise. Around the time you get access to the stock market you will probably have maxed out the interest on your property at 15% for this version. If you then compare it to the different stock market profiles you will get a average gain of:
Max property interest: 15%
Low risk profile average: 6.25%
Medium risk profile average: 7.5%
High risk profile average: 4.2%
So if you just put money in the stock market you will on average earn less than just putting it in property. It also shows that high risk is not worth it long term due to the low average return rate and the 1% chance of losing it all. These chances would maybe be good for a casino where someone will try once or twice per opportunity to get more spending money, but not a stock market where you expect a weekly increase.
For the math on the averages just multiply the chance with the profit/loss. For medium risk:
25% for +30%, 25% for +15%, 25% for +0% and 25% for -15% becomes:
0.25*30 + 0.25*15 + 0.25*0 - 0.25*15 = 7.5
It is probably a good idea to put the averages in line with interest with slightly higher averages and larger extremes for higher risks.
Two other points, could you put in reminders/hints/tutorials of how the financial systems work, specifically the advertisement system since I kind of forgot and dont know whether I should put in more money than is required.
Also the money grind is a bit extreme so maybe try to put the upgrade prices and prices for quest items a bit in line with what somebody with a fresh start would have. (Maybe make it a percentage of real weekly earnings rounded to the closest 100, like the camera for Rita requiring 150% of real weekly earnings) I personally have no problem with the high prices for accessories, clothing and the like. Those are nice rewards to work towards. (With real weekly earnings I mean earnings after the college takes it share)
But it is your game so make of this advise what you want.