Good advice from everyone, and good luck on the NFCU application.
I agree you are best to wait on any other apps, the CapOne and Citi DC are good cards to have for now.
The Citi card will likely be able to do SP CLI after a few months. Check back on your online account, follow the Account Management link, there is a Request a Credit Line Increase link. If the language is "A credit bureau report will not be requested and you will recieve an instant decision" then it will be a SP request. There is a time gap after you make such a request, before you should try again, like several months, but it is available to check whether that $1k DC can grow.
As to the APR rate? I would not use that as a criteria to close accounts. Credit One deserves to be closed for other reasons, but the Cap One and Citi accounts should probably be with you forever. After a year or so, you can try chat with Citi to see about lowering the APR, that sometimes works. Capital One, to my understanding, does not lower the APR on existing cards.
Regarding your next card, early next year. I would strongly suggest putting the Chase Freedom card at the top of the list. The 5% rotating categories are useful, and with Chase 5/24 rule you want to get the card before you get app crazy and go over 5/24 
@NRB525 wrote:Good advice from everyone, and good luck on the NFCU application.
I agree you are best to wait on any other apps, the CapOne and Citi DC are good cards to have for now.
The Citi card will likely be able to do SP CLI after a few months. Check back on your online account, follow the Account Management link, there is a Request a Credit Line Increase link. If the language is "A credit bureau report will not be requested and you will recieve an instant decision" then it will be a SP request. There is a time gap after you make such a request, before you should try again, like several months, but it is available to check whether that $1k DC can grow.
As to the APR rate? I would not use that as a criteria to close accounts. Credit One deserves to be closed for other reasons, but the Cap One and Citi accounts should probably be with you forever. After a year or so, you can try chat with Citi to see about lowering the APR, that sometimes works. Capital One, to my understanding, does not lower the APR on existing cards.
Regarding your next card, early next year. I would strongly suggest putting the Chase Freedom card at the top of the list. The 5% rotating categories are useful, and with Chase 5/24 rule you want to get the card before you get app crazy and go over 5/24
Thank you for the information, good to know that citi can lower apr. You're right with Cap1, the apr is for the life of the card.
I've seen nothing but thumbs up for CF - definitely one of my next choices