Seeker, deconstruction and reconstruction at a molecular level is in essence a form of molecular manipulation where say you ignore the concept of "can't create something out of nothing". So with this you could shrink or increase someone or somethings size, change the structure, even destabilize the molecules hence creating an explosion. Anything this this drastic and close to molecular manipulation is banned.
Also yes Mind manipulation, fire manipulation and metal manipulation are reserved among the others, so no one can call dibs on them. All Asylums are taught how to be efficient in teleportation and healing alchemy, as such it is pointless for it to be a specialization.
Angel didn't manipulate time, he manipulated a person's perception of time and as such left that person catatonic for a time being.
Rtron has played shadow manipulation before so he is aware of the limitations though I have placed a few more. For one you can not travel through your shadows, the ability to spy on a person via his shadow will be limited in range, this range will extend if you are a hunter. Giving sentience to a shadow is difficult and borders on taboo alchemy, its better if you twist this around as "it may be that she gives them sentience or she may have slight schizophrenia." This will also add a sense of curiosity and amusement.