Not doing much work on the news app in Arc but have done and currently working on a news clone in Prolog.
> - Search functionalities
A while back I added a simple search bar. There's no indexing but it should work fine for smaller instances. Have you tried it?
> - Add new buttons features that exchange data with other services
I implemented data export in JSON similar to the HN API in a fork a while back. That wasn't complicated, and I could probably add it to the Anarki repo if it's something you could use.
By 'exchange', do you mean sending to or receiving from? What services were you thinking of? The news app also has RSS feeds which could fit this.
> - Login with Google Account
For a starting point, it might be good to look at Racket's OAuth package.
> - Best practices on backups (since people are adding links) and protocols to avoid data loss and restore if I need to re-install.
All the data is just in the `www` folder (or `anarki/apps/news/www` as it is currently). A backup can be as simple as taking a copy of that folder. Restore is just copying a backed up `www` folder back into `anarki/apps/news/www`. Best practice would probably involve having automated backups and also doing off-site backups once in a while.