Okay, first, let me make a comparison here. In the video game "Champions of Norrath" there are stones called Misty Globes. When these stones are put into a weapon, the weapon moves faster, allowing you to make more strikes in less time. There are different ranks of Misty Globes, and the better they are, the faster your weapon. Problem is, the fastest of them causes your weapon to move so fast, that the game literally fails to register the hit. The attack moves so quickly, it just "whiffs" them.
Okay, now then, let me make this comparison using your examples, and expanding on them a little bit.
TA Scene #1: Your Enemy is under the effect of Concealing Amorpha, and has a Astral Construct out. CA will expire on him in 2 rounds, AC will expire next round. You use TA for 3 rounds.
Result: Nothing happens to his durations, TA had no effect on him.
TA Scene #2: You have an Astral Construct, an Energy Wall, and a Force Screen active. You then manifest TA for 2 rounds.
Result: AC and EW do not have their duration lessened, due to the fact that they have no part in the TA. However FS does have its duration lowered, since it is an effect on your person.
TA Scene #3: You start out a battle by using TA for 2 rounds. On the first round you manifest an Energy Wall.
Result: The EW does not have your second round count against its duration. This is due to the fact that, after it has been manifested, it is separate from the TA.
TA Scene #4: You manifest Energy Ball, with no Metapsionics, on an area that contains enemies, while under the effects of TA.
Result: TA specifically states that the power will fail to affect them. I imagine it as being a case of the fact that you are manifesting it so quickly, that the effect passes them by too fast to really feel it. In essence, you whiff them the same as in the comparison at the top of this post.
TA Scene #5: You manifest Delayed Energy Ball, triggered to activate when creatures, on an area that contains enemies, while under the effects of TA.
Result: Delay slows down the blast to when the power registers the enemies. Because Delay gives the power a duration other than instantaneous (it would have a duration that reads like Delayed Blast Fireball), the fact that it is a power separate from you kick in. It now is like Energy Wall, or Astral Construct, as above. It is not a power in effect on your person, like Force Screen, thus TA does not affect it once manifested.
To make one last comparison, let us look at a CO trick for Sorcerers & Wizards. Time Stop + Stored Lightning Bolt. Time Stop dos not let you affect creatures, but does let you affect terrain (to a point). Stored Lightning Bolt lets you "charge" the ground, instead of just hitting your enemy. Once Time Stop lapses, Stored Lightning Bolt registers that someone/thing in touching the charged material, and it goes boom. As far as most onlookers are concerned, this all happened at the same time, only you notice that time has passed, but that is because your whole body is watching it in hyper-speed.
That's what Delay Power is doing for you, the difference being that you can just "charge" an area in general, without having to target a particular object.
This is CO. Mix in Ardent with Dominant Mantle (Time) and Metapower (Persisted TA), along with a PP recovery method, and you hit immediate TO.