How to disable the mic

Take a look at the winning odds. You can see them before the race in the player list, after selecting your car. Players with high win rates have lower odds and vice versa.

If you were getting $1000 on top of your initial $2500, it means that the odds of the player you bet on were 2/5. If you placed your bet on a player with 3/1 odds, you'd triple your wager.

There currently isn't a way for a crew to share property. You could all give money to one person to own an apartment you could all go to assuming that person was online. There is no practical way to share a garage as any vehicle driven into a garage becomes a personal vehicle of the owner and they can only have one personal vehicle out at a time.