I think using magic mods and combat mods like Deadly Reflex unbalance the game,
I think that vanilla BGS games are all terribly unbalanced, and that it takes quite a few mods to straighten that out.
Supreme Magicka is highly configurable, and you could make magic much weaker then vanilla by changing a few settings. However, since vanilla has a fair number of spells that are nothing short of comedy, I don't see the point.
I agree that it gets unbalanced if you max out fighting AND magic, but again that is BGS' design, and must be fixed either by mods, or a decision to roleplay.