After several weeks of trial and error, I might have found a workaround or possible solution:
If you can get on without certain compulsory-apps, that came to your phone with Samsung's Edition of Android, you should consider disabling the following services in Android application manager:
- S Health
- S Voice
- Samsung Account
- Samsung Galaxy
- Samsung Link Platform
- Samsung Link Platform Connectivity
- Samsung Push Service
- Unified Daemon
Note, that if you disable 'Unified Daemon' and 'Samsung Push Service', 'Samsung-Account' and other Samsung-features also won't work properly any more. Keep in mind, that 'Geo News' also depends on the 'Unified Daemon'! Samsung's backup-/restore-features are negatively affected, if you disable one of the 'Link Platform'-services, but Android's features still work as expected!
The list above contains apps/services, that (for me) are highly suspicious of causing the described problem, but for the sake of completeness, here's the complete list of apps/services, I have disabled (not uninstalled - since this would require root-access):
- ANT Radio Service
- ANT+ Plugins Service
- b2b.hrs.android.lib
- BlurbCheckout
- ChatON
- de.pizza.lib
- Group Play
- S Beam
- S Health
- S Planner
- S Voice
- Samsung Account
- Samsung Apps
- Samsung Billing
- Samsung Galaxy (I don't actually know, what this one does, but the phone does not need it to work properly)
- Samsung GALAXY Apps Widget
- Samsung Link Platform
- Samsung Link Platform Connectivity
- Samsung Print Service Plugin
- Samsung Push Service
- Smart Remote
- TalkBack
- Unified Daemon
In the last 3 weeks, the problem never occurred again - and I'm not missing any of the features above. As a positive side-effect, there are no more lags or hangs on my phone any more...