Okay after a few hours I think I have found the solution to keeping fragments in place for everything and removing the action bar (for all devices) for the launch activity only:
Android Manifest:
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.company.app"
android:versionCode="1"
android:versionName="1.0">
<uses-sdk
android:minSdkVersion="7"
android:targetSdkVersion="19" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme">
<activity
android:name="com.company.app.LoginActivity"
android:theme="@style/NoActionBar"
android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
Where the style is defined as like so:
<style name="NoActionBar" parent="Theme.AppCompat.Light">
<item name="android:windowNoTitle">true</item>
</style>
That took a while to figure out because there is no Theme.AppCompat.Light.NoActionBar , the action bar is basically known as the title bar in older APIs, and when I applied that style to the activity itself (which I thought was the only way of using dynamic themes) it doesn't seem to work at all.
So hopefully this simple solution will keep the action bar for any other activities and it may help someone in the future :)