And that is all good and well but my point is more the utility of magic in TES compared to the combat of magic in DM. I'm pretty sure a few people are going to hate me for bringing this up but back in MW the list was much bigger and "combat spells" were Destrucion, Conjuration, some of Mysticism and some of Alteration, and Paralyze. Thats about half.
If you want to delegate that kind of an "epic-ness" system to the combat, thats fine. Again, I am not against it. But at the same time I don't particularly need to see my character shaking when he is opening a lock.
And I disagree for taking DM's magic system over TES's, though TES's could still be improved.
No I completely agree with you, in fact some spells need to subtle to begin with Illusion in Oblivion was to be frank entirely too obvious, and actually like to see a reverse. Think about this from the perspective of Paper and Dice Role-Play games, you have Gestures, Vocal, and Material components to all spells... For Illusion you'd want the exact opposite effect from other spells, at low levels spells would emit unwanted light sources, require excessive movements, and maybe even attention grabbing vocalizations, however as you leveled up these would go away, starting with the green smoke or lights, and the gestures would become more subtle, and you could mumble or quiet the vocal components, and eventually as a master you wouldn't even need them and the spell would happen pretty much at will.
On the split side, more complex destruction spells would warp the surrounding world, draw in elements, change the lighting, and have more effects the more advanced the mage, merely because of their destructive nature. The low level mage would merely create a small ball of fire, with nothing particularly special about it, a high level mage would have you questioning if it was just fire, or some new apocalyptic element ripping at the very fabric of space and time.
Most of these issues have already been addressed, and solved in the very rich history of Role-Play gaming, because of this, I severely doubt that Bethesda has any intent on improving this functions, it is a utility game, and in spite of Oblivion moving towards the graphical, this game has never really focused on graphics as a primary game point. That being said, yes,opening locks, charming characters, frenzying them, chameleon, invisibility, and similar spells should all have subtle to no 'tells' at higher levels, where-as more destructive and less utility or discrete spells should become increasingly graphically intense, perhaps even causing lightening, fire, and meteors to rain from the sky, fissures to open in the ground, and wind to reach hurricane force speeds... Although this is TES, so don't count on it.