You and the other pilot are equally responsible for avoiding collision. The see and avoid principle applies.
You saw, you avoided..........the system works horray!
See and avoid is just that you avoid collision..........nowhere does it say how much you will miss by.
If you felt that there was any element of danger/risk cause by the proximity of the other aircraft you should report an Airprox and let the experts debate the situation and come up with an opinion. That is what they are there for. If there was no danger then what is this about?
As for height to complete aeros........everyone has their personal minima........some display pilots can operate to 50ft above surface (subject to legal requirements).
Regards,
DFC