The spell only mentions making saves when you move the Sphere when you sustain, so I guess that if you move in the sphere space yourself the rulling that you did works fine.
This came up last night in a jailbreak. The druid cast Aqueous Orb to block off a corridor of guards and i ruled that they had to swim through the orb as they had to intentionally move through it thus creating a hilarious moving underwater battle with the paladin which was a lot of fun.
But looking over the spell text which is very long, i think i did this incorrect and they should have made a saving throw to bypass it completely even though they are intentionally trying to move through it. How would any of you rule this?
I think the ruling is correct. The saving throw portion only triggers when it is sustained. Otherwise creatures can swim or escape as normal while inside the orb.
A better question would be whether creatures can freely move into or through the orb if it's occupying space, but based on it's mechanics I'd say they can.