You should never ever give your birds huts, tents, hammocks, boxes, tubes etc.
1. Huts kill birds frequently due to blockages, strangulation etc.
2. They encourage nesting/hormonal behavior...as do other shadowy spaces. By presenting these, you increase the likelihood of aggression, cage territorial behavior, screaming and health complications, such as egg binding or egg laying (even if no male is present), plucking etc etc. Egg laying itself is risky (even if eggs are infertile).
They absolutely should not have these. They can sleep on the perch just fine.
This girl absolutely knows her stuff and I would STRONGLY suggest you watch these:
[ame="https://www.youtube.com/watch?v=EXUALzfFHt0"]10 Dangerous Bird Products You Should NEVER Buy! - YouTube[/ame]
In terms of "feeder".. you should generally NOT have cups without a cover, as birds can get stuck in the covered plastic ones...we had a member who lost a bird this way... Can you post a picture of your cage? That would help people make suggestions. Also, since you have more than 1 bird, I would get more than one feeding cup, as they can compete and fight over food when there is only one option.
Without knowing what type of cage you have, it's impossible to suggest..You say, "feeder" which also confuses me....