Re: conure question..
If Skittles will be well looked after, and Archimedes and Amadeus won't be at risk of neglect, I think adopting this Conure sounds like a grand idea.
Not knowing much about the dynamics of multiple bird households, all I can offer is that you are the only one who can decide whether to bring a new parrot into your home.
Personally, I don't think I could resist a Conure.
Only when the last tree has died,
and the last river been poisoned,
and the last fish been caught,
will we realise we cannot eat money.