With Kitkat your chances for a "complete solution" without rooting are pretty much zero: the Android project has definitely screwed up here. No apps get full access to the external SD card, which rendered a lot of them unusable:
- file managers: you cannot use them to manage your external SD card. In most areas, they can only read but not write
- media apps: you cannot retag/re-organize your media collection any longer, as those apps cannot write to it
- office apps: pretty much the same
The only place 3rd party apps are allowed to write on your external card are "their own directories" (i.e.
/sdcard/Android/data/<package_name_of_the_app>). The only ways to really fix that require either the manufacturer (some of them fixed it, e.g. Huawei with their Kitkat update for the P6) – or root (see my list of Other storage media tools for examples.
If you do not want to go the latter way (rooting), and the former way (fix by manufacturer) is not available, you can only do minimal things on Kitkat:
- use app2sd (which seems to be available on your device) to swap-out parts of your apps. This requires the corresponding apps to explicitly support App2SD, and only will "swap out" parts of the apps themselves; other parts of the app, including all its data, will remain in internal storage
- set your "default install location" to your SD card (see: Installing to SDCard by default). This will automate App2SD for all your new installations.
Apart from that, you could only hope and wait for a Lollipop update – which will not completely fix the issue, but at least slightly defuse it.
As long as you don't hit any storage limits, you might be mostly fine. Nevertheless, I recommend you already familiarize yourself with potential solutions for the day your data "hit the roof", so you won't be forced to "act in a hurry" then.
Other Questions with answers on "kitkat sd-card write" on our site, especially: Workaround for Android 4.4 not being able to write to SD cards?