Recommend security-first basic Linux Apps!

As part of the effort of making a “Chromebook-like” secure, autoupdating, cloud-native, “unbreakable” (but still free and privacy-friendly) Distro, I would like some of your recommendations on especially secure software, that could replace common ones like File managers, Archive Managers, PDF reader, Image viewer etc.

I am thinking of Loupe, GNOMEs new image viewer written in Rust, that opens SVGs in a sandbox to avoid issues here.

Memory safety, resonable simplicity, updated code, these should be requirements.

Any other recommendations? Thanks guys!

Btw Flatpaks are working now! Come and test Secureblue!