At this point the tor binary is in version 0.2.8.7.1. Ricochet (https://ricochet.im) hasn't been updated since February and is using tor version 0.2.7.6. There are some major updates between versions. Is it ever a good idea to simply copy the 2.8 binary provided by the official tor repo and overwrite the ricochet binary? I'm not clear on the security/functionality risks involved. Needless to say, I haven't tried this yet.
The list of recommended versions contains 0.2.7.6, so it is not officially outdated.
If you want to use a newer version of Tor with Ricochet, just copy or link the Tor binary to the directory where Ricochet lives and start the software. Below you see a screenshot of Ricochet's settings which tells you that it runs with Tor version 0.2.8.8. I used the method above to get a newer version of Tor.
Yes, you can make a drop-in replacement of the binary files, as far as I know Tor is just bundled into the Ricochet, it's not patched and/or tailored in source to fit the needs
UPDATE: Take a look at it's source code - there's no shipped or included tor binary. There's only a messenger itself