I also wondered if there was an equivalent to tumbling past someone to avoid the attack of opp.Acrobatics says you can use it to move through an enemy's square and avoid being hit. It seems like if you can use it to move through an enemy's occupied square, you should be able to move around it in the same way. Right?
Check again - Tumble Through doesn't actually say anything about preventing reactions/attacks of opportunity. It *only* lets you move through enemy spaces.
The bit in the failure condition about triggering reactions is to cover the possibility that you started or moved adjacent to an enemy, failed your tumble through, and therefore didn't "leave a square within the enemy's reach." This is just saying that you trigger reactions as if you did anyway.
There is a Mobility feat for rogues that lets you Stride for half speed or less without provoking, but that's a different thing.