Welcome, Matt (no pun intended)!
Wow, that's a lot of questions to consider! I'm pretty new to photography myself, but I love the entire process!
I guess the reason I do this is to capture what I see. You know, you see something... milkweed pods releasing seeds, a feather in the sand, rows of corn covered in snow... and there is something about the play of light and shadow and spirit that just makes you want to keep it forever. It's kind of like a journal.
So, that's how it is for me!