I was waiting for one of the regular steel shooters to reply (I have shot it before and will again, but it has been a while), but since it has been 10 days since the original post I will go ahead and try to assist.
The group that shoots at Magnolia is not an official Steel Challenge affiliated club, hence the "Renegade" name. They don't use the officially recognized divisions, but instead just have 3 divisions per Cliff's post
here - Open Centerfire, Limited Centerfire, and Rimfire.
Open would be anything using any sort of optical sight (or laser) and probably any type of compensator or porting as well, while Limited would be iron sights and no comps or ports. Rimfire is just that, although I thought they separated optically sighted and iron sighted rimfires as well, but apparently not.
I'm not sure what they would do with a flashlight, honestly. It's not an optical sight and I can't see how it would be an advantage (unless the match were at night!), so maybe Limited but I am not sure. It would add some weight and would technically not be allowed in USPSA "Limited" division, but I don't know that they would be that strict. Hopefully someone will come along that can give a better answer... PM Cliff or ScottW.
Although not used by the group in Byram, the official Steel Challenge rules can be found
here. Under them, there are "Optic" (optical device of any sort, including lasers) and "Non-Optic" (iron sights, fiber optic inserts ok) for rimfires, and in the centerfire main event, basically anything goes and then there are a myriad of categories recognized within, including "Open Revolver", "Iron Sight Revolver", "USPSA Limited", "IDPA Custom Defensive Pistol", "IDPA Stock Service Pistol", "IDPA Enhanced Service Pistol", "Cowboy Single Action".
See pages 8-10 at the rules link. Most of these are relatively straightforward, but since they don't really answer the question, I'll save that for another day.
Sorry I can't be of more help.