Minecraft – How to prevent players from having a specific item in their inventory

This answer was written prior to the release of 1.13 and "The Flattening" that came with it. An updated answer can be found here.

You're actually pretty close, and definitely on the right track. Instead of {Inventory:[{id:<block ID>,data:<data value>}]}, use {Inventory:[{id:<block ID>,Damage:<data value>s}]}. The s after the data value is important since it's stored as a short, not as an int. (As an aside, if it were stored as a byte, you would append a b instead.)

Seeing that you were desperate for a true answer, I built a prototype (Still adding the torch item drop prevention, as the one I made broke due to the execute detect function being really buggy).

This prototype does what you want for the most part. It uses 3 scoreboard objectives: Jump, jumpCool, and Torch.

Jump is basic. If you jumped it sets jumpCool to 5 and then sets itself to 0. jumpCool is the cooldown for when the light can be created. If you jumped it's set to 5, and if there is air below you it is set to 5. Torch is set to 1 if you're holding a torch.

From the prototype some issues do occur, one being that for every block torch's can't be placed on, you need to add a command block to blacklist it.

Here's the prototype setup and commands: http://imgur.com/a/i9Yo2

The command block not talked about in the above link is the broken drop protection. Basic armor stand to block access to the torch, and then have a despawn timer for the armor stand and then delete the torch along with it. Still working on that so when it's done I'll note that it is.

Finished version:

Download: https://www.dropbox.com/s/dn9q5xak462rhq9/Creative%20Mode%2015w32.zip?dl=0