sounds like you already are familiar with Android, and depending on which carrier you are with, you will just need to get rid of the Bloatware.
Fortunately with the S5 it is super easy to do...
Settings/Applications/Application Manager/ALL
Coast down through that huge long list and turn off the bloatware.... It won't be uninstalled, but at least it can be Turned OFF and out of your way. Best of all, if you happen to need it back, just go to
Settings/Applications/Application Manager/Turned OFF
and find the app you need and turn it back ON.
Kit Kat has a few minor features deleted that we used to enjoy. Can't block SMS messages from specified phone numbers... However, if you don't mind using an app to replace the OEM message app, Phone Warrior SMS can block incoming SMS messages once you receive one and it stores it in its' own cache.
https://forums.androidcentral.com/e...ls?id=com.visinor.phonewarrior&token=BkwgAuFT
Lots more too... that is just off the top of my head right now.