I'm going to take the jump to a custom rom on my s4 mini. Yet I've tried to enforce my privacy on a non-rooted samsung android 4.2.2 with NoRoot Firewall, SRT: AppGuard and F-Droid apps.
From my own search OmniROM would be the one I'd like to go for but it is not available to the s4 mini. Next one wold be Replicant that is neither available to the s4mini. CyanogenMod + freecyngn would help with the proprietary parts, something I'm also looking for (as some custom roms use e.g. Nova launcher) but doesn't get rid off googles own call back/tracking/identification services in use (I don't/won't use).
Thanks for your help in advance!