The point of sudoku is to use logic to solve the puzzle, not guessing. Some of your "techniques" involve guessing, which defeats the purpose. All of your logic-based techniques have already been discovered and enumerated and have standard names. Furthermore, they are the very simplest of techniques. And you still need to differentiate between a notation method (pencil marks, dots, etc.) and an actual solving technique (which involves one or more logical steps to eliminate candidates from at least one cell).
Here's an analysis of your "solving methods":
"Low-hanging fruit" = naked single
"Scanning" = naked single
"Arrows" - not a solving technique (merely a method of notation)
"Left-middle-right" - not sure what you're doing here, but it appears that you are basing this on an invalid assumption about column/row positions
"Dot method" and "casual dots" - nothing more than a notation method
"Quick checks" = hidden single
"Line-end digits" = hidden single
"n-Blank" = locked candidates
"Complete dots" - notation method, not a solving technique
"Line alternatives" = guessing (NOT sudoku)
Without guessing (what you term "trial and error"), you won't solve any but the easiest puzzles with your methods. As I said, sudoku is logic, not guessing. And I would be willing to bet that the puzzles you refer to as "Black Belt" (not a standard term in the sudoku community for puzzle difficulty) are not really difficult at all.
I suggest you go back to the links that David P. Bird referred to you early in this thread and work through the techniques (and learn the standard terminology while you're at it). Another good solving guide is here: http://www.sudocue.net/guide.php
You will find that pencil marks (or "complete dots", if you prefer) are the key to nearly all of them.
