This probably isn't exactly what you're looking for, but it is the most extensive database of crossword clues (American) that have been used historically:
http://tiwwdty.com/clue/ - it can be integrated into your crossword construction software or (I believe) used as a standalone database.
This web site (cruciverb) has an interesting commentary about clues under the "Sage Advice" menu. Also you can look up words/clues on several sites including this one, crosswordtracker.com, crosswordgiant.com, and others.
I can thing of a few different "types" of clues, though we don't usually categorize them as such:
Straight definition - IRATE = angry
Explanation that's not a direct definition - DOG = family pet
Misdirection or "trick" - DEE = Capital of Delaware? [clues like this often have a ? to signify that it's a joke of some sort]
Fill in the blank FITB = ELEPHANT = ___ in the room
Most good puzzles will have a variety of these, with harder puzzles tending to have fewer FITBs and direct definition, and the other clues will be more vague (but still accurate).
Not sure this helps, but there you are.
