Pray tell: how many levels of existence must one pass through to achieve godhood?
If there are multiple levels, if I do enough good on level 3 but mess up level 4, do I have to go back to level 3 again?
Please explain or provide a reference that will explain the whole afterlife (afterlives?) progression as you understand it.
Your view of Mormonism is flawed
Mosiah 2
20 I say unto you, my brethren, that if you should render all the thanks and praise which your whole soul has power to possess, to that God who has created you, and has kept and preserved you, and has caused that ye should rejoice, and has granted that ye should live in peace one with another—
21 I say unto you that if ye should serve him who has created you from the beginning, and is preserving you from day to day, by lending you breath, that ye may live and move and do according to your own will, and even supporting you from one moment to another—I say, if ye should serve him with all your whole souls yet ye would be unprofitable servants.
22 And behold, all that he requires of you is to keep his commandments;
----
You might find reading the whole chapter useful. http://scriptures.lds.org/mosiah/2
We don't 'earn' what God give us, we are constantly in debt to God no matter how much he blesses us for whatever good we do.
There is no series of lives, we don't teach reincarnation. As for what comes after this life, we don't have a lot of detail, but there is an overview at http://ldsfaq.byu.edu/emmain.asp?number=144 that should answer your last question.