Caged by a Secret Killer: Is there a More Thematic Sudoku for this Channel?

Today's Puzzle:

If there was ever a puzzle created for this channel and its theme, this may well be it. From the constructor and the puzzle's lore:

Oh no, you've been locked inside a sudoku grid by a crazed maniac who gets thrills out of forcing people to complete logic puzzles. Use your wits as well as knowledge of some sudoku "secrets" to break free. Puzzle creator is not liable if the puzzle breaks during your escape.

Link to Play Along:

Caged by a Secret Killer by PhoenixAki http://tinyurl.com/SudokuSleuthCagedByAKiller

Rules:

Normal sudoku rules apply.

Cells in cages sum to the total in the top left corner. In this puzzle, cage totals are given as letters, whose value must be deduced. Each of the 4 letters has a unique sum (i.e. A can't be the same as C G or E).

Digits can not repeat along the positive and negative diagonals.

Cells connected by a green line must differ by at least 5.

Cells connected by a white dot are consecutive.

Inequality signs (> or ^) point to the smaller of 2 digits.