Aside from the whole entitlement thing, the problem with O'Flynn is that he is from Blarney, while Kelleher is from the White's Cross/Carrignavar area. So they are geographically located close to each other, but leave the city empty. And while O'Flynn has served on the city council, he's never broken 1,000 votes.
The FF candidate needs to be solidly city based if they are to credibly challenge for a second seat. Run someone like O'Flynn and it just boosts O'Brien's and Lynch's vote.
I'm also sure that Micheál Martin knows O'Flynn well and will ask himself if he wants him as a back bencher.
Julie O'Leary is a strange one to be honest. Everything I have ever seen her say or write suggests she would actually be more at home in The Green Party or the Labour Party, but maybe she has made the calculation that she has more chance of achieving what she wants in Fine Gael than in a small party.
O'Leary is running for the city council and how she does there will say a lot. On paper, she has a tough fight as her running mate looks better able to pick up votes in the parts of the NW LEA that lean Fine Gael. But she's certainly a hard worker and engaging, so I wouldn't rule her out. However, if she can't pick up that council seat, you couldn't fancy her chances in a Dáil election.