As written, temporal acceleration gives you a round. The “next round,” from the perspective of a creature in temporal acceleration, is immediately after temporal acceleration ends, at which point the Linked Power occurs. Synchronicity goes off, you get whatever action you readied, and then you get your move and standard actions from the original turn in which you manifested temporal acceleration too.
However, I am stating for the record that I don’t suggest actually using synchronicity, particularly in conjunction with Linked Power, and especially not with Metapower. Getting three standard actions in one turn, as you suggest with your temporal acceleration, is pretty bad, though it does cost at least 13 PP. Adding extra standard actions to your next turn, as an immediate action (grip of iron, e.g., is 1st-level and manifests as an immediate), for just 1 PP (Metapower), tends to break the game into itty bitty pieces.
Stun, Daze and similar stuff don't impede your movement...
...they make your mind funny.
While you are stunned, there's nothing holding your body to move. You just can't think right to actually do something. If you take a really hard blow to your head, that won't make your body harder to move - it will make your brain go gonzo for a few secs, before you became aware of what's really happening.
Stun is not about movement, is about senses of what's going on.
Freedom of Movement makes "your body work right", not anything else. It allows you to move, but not allows you to think. You can't think if you're dead. Or Stunned.
Paralysis don't block purely mental actions, so it don't block "thinking".
Slow makes your body... well, slower, but it doesn't affect your thinking.
Web is... well, a web. It hinders your body, not your mind.
Stun, Daze, Dazzle and similar stuff, on the other hand, makes your senses go wacko, so they aren't really blocking your movement. Stun never stopped you from moving, it just stopped you from thinking for a while - and since you don't think, you don't act.
So, the point is,
If something affect your senses, Freedom of Movement can't help you.
Think like a "Houdini Effect". Houdini can escape from almost anything, considering that he
knows what's going on. If you throw him with a concussion inside a closed coffin... well... he will stay there.
So, to determine what Freedom of Movement removes or not, use a simple rule:
Why I can't move?
If you can't move because a spell or something is hindering your body to move, like Web, Freedom of Movement can help you.
If you can't move because a spell or something is making your brain go gonzo, like Stun, or because your body becomes something that can't normally move, like stone from Flesh to Stone*, it won't help you.
*Flesh to Stone don't impede your movement, it merely limits you to the movement that a stone statue is allowed to do. A "Freedom of Movement"-ed and "Web"-ed person would become a completely untangled stone statue.
Also, read Freedom, the 9th level spell:
The subject is freed from spells and effects that restrict its movement, including binding, entangle, grappling, imprisonment, maze, paralysis, petrification, pinning, sleep, slow, stunning, temporal stasis, and web. To free a creature from imprisonment or maze, you must know its name and background, and you must cast this spell at the spot where it was entombed or banished into the maze.
Emphasis mine.
Freedom removes a bunch of effects, like Flesh to Stone and Stun. It would seem rather... strange to say that a way lower-level spell can do almost all the things that a 9th level spell can. Freedom is Freedom, not Freedom of Movement.
Best Answer
Short answer: The rules don't say. Choose whatever you consider coolest.
Somewhat longer answer:
I would expect yes. Effects are said to travel with their subjects, so they can explicitly exceed for example their range once they've been cast. An effect with a non-concentration duration is therefore a feature of the subject and should share its frame of reference. You obviously can't actually issue commands to the subject while it's in stasis.
That's my expectation, but I think the real answer depends on how you conceptualize temporal stasis. Ask yourself this: Can a subject of temporal stasis be stripped of its gear? Neither the spell nor the rules governing targeting specify, but I consider the answer to be "no". And I construe an ongoing spell effect as just another thing that is temporarily part of the subject, but that's not the only valid interpretation of events.