Lyft Exspress Drive: Personal Miles and Rental Rewards

Hello. I'm going to start driving for you soon but I have 2 questions I'd like to ask first. I have read up on both questions extensively but keep finding conflicting reports on both.

1- Concerning personal miles. During my research I've scene 3 different answers addressed when it comes to personal miles. They are as follows: You earn personal miles the more you drive, you are charged $.25 cents per mile, and you have unlimited personal miles. Can you shed some light on how this works?

2- Concerning Rental Rewards. During my research I've come across conflicting reports on what these rental rewards are. One said that it's a tier rewards program and once you hit 75 rides its cheaper, 90 it's even cheaper, and 110 it's the cheapest. The other said it's free once you hit 75 rides. I know I'll still have to pay a deposit and taxes/fees but this is the most important question. What exactly in numbers is the Rental Rewards?

Thank you again.