Well, the tactical map could benefit of some improvements. I guess one of the most demanded is the terrain modifiers (to accuracy, dodge, movement, etc, depending of a forest tile, hill, swamp, etc.).
About your suggestion, it seems to potentiate the RPG elements. I think any element added to the tactical map will increase adventure. The idea of traps sounds nice, depending on the context (a lair, an ancient ruin....). Although it might take to think: well, why not create also a "detect traps" skill or spell? 
RPG players know how little sense there is in killing a wolf and finding a pelt (wich is ok) but also 3 coins and a knife, but that kind of loot may be accepted if not abused.
In that way, finding these chests you say....well...again, depending on the context, a chest in the middle of a tactical combat might make sense or not. Randomization in this case is not good. I mean, a chest in a dragon lair might be ok, but in a spider lair?
To tell you the truth, I would really like to see an expansion of the tactical map, in the way that you get into a lair, and you have to really explore it, through various tactical maps, with different enemies, the traps you said and all the rest of RPG elements. Some lairs might be as complex as imagination rules.
BTW, take in mind that having that RPG lair system would distract from the 4X part of the game, but why not? A mod/expansion with explorable lairs could be awesome.