will I be able to send Narrative NEP-5 tokens with ledger? (once ICO arrives)
Yes, you can send/receive NEP-5 Tokens with the NEON wallet and the Ledger Nano S. The NEON app will always be updated as soon as there is a new token.
Does it mean that I need to download and re-install Neon wallet each time when new token goes live? Is there any option to avoid it (import contract address or something like that)?
At the moment yes, you need to install the newest NEON version when a new Token goes live, maybe that will change in the future, I don't know. But that's done in less than a minute.