Yea, it sucks to get one all back in and have the pump seal pop out.:D
They actually make a retainer for that and I have used those before, but never had a bushing pop out after the red Locktite.
Reusing a converter is never recommended, but a man has to do what he has to do.
If it worked before, it will probably be ok unless it dumps garbage back into a new trans.
Flushing a converter is better than nothing, but it doesn't do much really.
If you didn't have a bunch of garbage in the pan when you took it apart, then the flush is better than nothing.
If there was garbage in the pan like metal flakes the converter should be replaced.
Color of it means nothing really.
Don't forget to flush the cooler lines both directions with solvent a few times.
(gas works too, but just be careful about the mist that comes out, as it is highly flammable)
Both directions tends to get more junk out of the nooks and cranny's.