Does flashing stock ROM via Odin delete phone data?
None of your internal storage files i.e. Photos, Music, Videos, Docs etc., will not be removed until you do a repartition of the device using Odin. Your phone will be restored to perfect condition; just that all your personal information will be gone such as contacts that were on the phone storage and apps.

But I'm not responsible if anything goes wrong. Do it at your own risk.

OR

You can flash a custom recovery using Odin and use the MTP feature of the recovery and move the required files (which I assume would be safer).