Oxygen control wouldn't be an effective weapon. Taking the oxygen out of someone's lungs will be far more effective than just suffocating them, but it still takes about ten seconds for them to fall unconscious. If they have a weapon, they could easily kill you. If not, they could probably do enough damage to get you to stop focusing on the spell.
Of course, if you could just stop someone's metabolism (which isn't really distinct from fire), you could stop them pretty much instantly.
I don't think that can be considered time-travel. Also, it could still do a lot. It won't necessarily break the story, but it will have a big effect on what you can and can't do. Industrial espionage would be unstoppable.
Magic reflection seems near suicidal. Can you use holy magic to heal so you could actually practice and use it in situations that aren't actually life-threatening?
I think you could give someone an stroke with water magic. I don't know how fast that is, but I don't think they'd be able to trace it back to you, so it would be good for assassinations. Of course, if you do it enough, you could instantly kill someone.
Emotion seems pretty powerful. Exactly how specific is it? Can you manipulate someone's fear in such a way that they're guaranteed to run, rather than attack?
It's really hard to say what is and isn't overpowered without knowing how much power it has. How much mass can you magically move? How much energy can you create?
The groups don't seem to have any real internal consistency. For example, carbon dioxide seems to be under ice for no reason beyond that it has a solid form, just like everything else.
Freezing fire is impossible since it doesn't actually mean anything. Fire is just a chemical reaction. If you make them stop reacting, that would be putting the fire out, not freezing it.
Also, when you say classical states of matter, what does that mean? You can't control water in its bose-einstein condensate form?