Umm... the trail that Light left was based on his testing of the death note. It wasn't planned. Don't tell me if you found a book that said death note you'd immediately begin plotting how to use it without getting caught (assume an era BEFORE you watched this anime) I'm sure you'd probably do something like, "Let's write the name of that asshat at my school" or something.
Also, unlike most anime chars, Light doesn't go, "Hmm... what do I do?" He usually goes, "Do I do A, B or C?"
Yes his arrogance was his downfall, people don't like the ending, but it makes sense. Ryuk was to write Light's name in the book.
On another note, melo and Near seemed to be shadows of Light and L. Melo seemed to be similar to Light and L (dominantly light) and melo seemed to be a shadow of ALL the quirky side of L, but add some random autism and coin flipping. Melo geared up towards his goal and did what he needed to do. (Even if it seemed cruel etc) Near hid in the background going, what do I do now? Near's a pussy. I refuse to believe anything else.
Honestly, near and misa were the ones I hated THE MOST in this anime. Even Ray Penbar and those other random characters excited me more than those two retards.