a) Yesterday, he went to the haunted house --the one that we are all afraid of--to look for his missing ring.
'that we are all afraid of' tells us that we are still afraid of the haunted house.
'that we were all afraid of' tells us that we are no longer afraid of the haunted house.
b) If I knew that was going to be the last time that I'd see you draw picture of a man who sees god for the first time, I would have taken a picture out of your painting.
The man in the painter sees God for the first time, so use 'sees'.
c) You have always told me (that) you don't know what it feels like to be old and on wheels. Now I found way to show you what it feels like to be me.
You don't know how it feels or You don't know what is feels like. (general fact)
d) Where did you learn a feat like that? I mean, where did you learn how to disable your enemy like that before he takes his move? It was amazing.
It was amazing: What you did was amazing.
It is amazing: What you can do is amazing.
e) Look, (during) my second week in/at CSI you told me (that) when a cheating spouse is murdered there's always two suspects at the top of the list: the lover and the betrayed.
It's fine. I added in the omitted words, and changed the punctuation. (Hey, by the way, I saw that episode. It was amazing!)
f) I asked the mechanic one question about how that machine works and to my surprise that mechanic couldn't answer my question.
General fact: How the machine works.
g) When I was a child, I wish I had a mentor who could show me the purpose of life.