Even something as broad as Location would be helpful.

As would being able to flag a LinkedIn contact in DEX for syncing (and so open up room to sync someone you can select yourself).

Yes, AND an option to allow people that you're corresponding with on LinkedIn be automatically included on the contacts to keep up to date.

I'm finding the location data on LinkedIn is super inaccurate, and Dex keeps overwriting my new location when I correct it. Super annoying!

Add an option to selectively sync specific information as well to avoid overwriting existing fields.