The Investment system in the game will allow you to open up doors etc much quicker.

The best way to make points is to invest when the price is under $0.01 and to wait for it to 100x. Ideally wait for a market dump, buy as much as you can at $0.01 and then sell when you have about 800K to buy all the doors!

Another method:
Wait near the terminal, wait for a green headline then buy as much as you can.
Wait 3-4 seconds then sell all.
Repeat this until you have made a lot of points!