Bonfire intensity is some static value which I don't know the effect. I've never played a DS game. This is what I do know:
Bonfires are used in the game as a checkpoint and warp point. You find different bonfires, and are able to travel to other bonfires you've already found. You also return to the last bonfire you visit, after you die.
To increase the bonfire intensity, you will need to play through the game on NG+, and visit the same bonfire as you found in the previously completed playthrough. This will increase the value by 1. So if I found a bonfire in the previous, and found and activated it (light it) again on the next playthrough, the intensity value will be 2. Again, I don't know what exactly this affects.
Torch Time like 8Ball said is the time left for your torch. It's useful for dark areas, and lightning other areas that hold torches. They don't have any significant effect on the game, but it helps going through some areas.
Anyway, I hope you finish the Editor soon. There are a lot of things that are insignificant compared to what is really important, which is the item editor. Images, and such are not much of value, and can be improved in a later version of the editor.