I saw him picking at the side of the filter intake, and he seems pretty plump. So I don't think that I will have a problem with feeding him... And I will be taking all but abour 6-8 males to a LFS.
They should be fine. Why not give them a chance in the tank before you confine them again. I bet you will find they are doing great in the tank itself.
The person I got them from said that he had all of them in a tank with a power filter. So I'm not really worried. And they seem much happier, and some of the larger ones are startign to show black and orange now that they are in the tank.
By the time they start showing some color, endlers are ready to contend with the typical hazards of an aquarium. That does not mean they are ready to live with large aggressive fish but just that they can deal with filters and similar hazards.