There are no specific rules for edge cases like this. In Pathfinder the GM is expected to rule in a way that makes sense.

I find in cases like this, combining what's obviously realistic with a check leveraging even tangential RAW that at least nominally makes some of it under the control of the character is good.

The way I'd rule off the cuff if this was presented at a table:

• A six second round combined with falling means no, you don't automatically get a full attack.
• Pathfinder has a Fly skill. Most people don't have it, but there is one. Make a Fly skill check - if you hit 10 you get one attack, and you get an additional attack for every 5 points over 10.
• This assumes it's a deliberate thing - like "jumping" instead of "falling" - if a monster did the teleport as a surprise this check would be 5 points harder.
• You can maybe sub in Acrobatics, but again at 5 points harder on the check.

Not "no," but not "you can do anything you want just because you asked" either.

There Isn't Any

The conjuration arcane school spell-like ability dimensional steps says

At 8th level, you can use this ability to teleport up to 30 feet per wizard level per day as a standard action. This teleportation must be used in 5-foot increments and such movement does not provoke an attack of opportunity. You can bring other willing creatures with you, but you must expend an equal amount of distance for each additional creature brought with you.

However, strictly speaking, there's no movement associated with teleportation. Movement involves a creature using its speed with a movement mode (i.e. burrow, climb, fly, land, swim)--not on the creature's ability to travel from one square to another--, and only distance is associated with dimensional steps, not speed with a movement mode.

In other words, don't worry about it. There were no attacks of opportunity to provoke except from the activation of dimensional steps as a spell-like ability, and the ability ends up simply providing excess unneeded information.