Sorry, I don't understand the problem. Why not use "Shadow Omnidirectional" if it works fine?
http://www.imagebanana.com/view/06dosd14/shadow.jpg
When i use only "Shadow Omnidirectional" the shadow are unrealistic. The shadows look like from sunlight not like from the cartlight. If it has a lot of trees, you drive in complete darkness, although light. And "Omnidirectional" has no shadow, this is also unrealistic. I don't understand this lightning from skyrim.
Only a mix from both "Shadow Omnidirectional" and "Omnidirectional" is a moderately useful result. But "Omnidirectional" works only a few meters. I have to give up my plan.
If I throw a burning vanilla torch to ground, and then be carrying instead of equip, it behaves exactly the same.