Coordinatorlayout+collpasingtoolbar+recyclerview+editText not working as expected

First of all sorry to bring up another similar issue. But none of the other questions could not answer my challenges. I created a github project here https://github.com/winster/collapsingtoolbar.

activity_scrolling.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.design.widget.CoordinatorLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@android:color/background_light"
        android:fitsSystemWindows="true"
        android:layout_above="@+id/footer"
        >

        <android.support.design.widget.AppBarLayout
            android:id="@+id/main.appbar"
            android:layout_width="match_parent"
            android:layout_height="300dp"
            android:theme="@style/AppTheme.AppBarOverlay"
            android:fitsSystemWindows="true"
            app:expanded="false"
            >

            <android.support.design.widget.CollapsingToolbarLayout
                android:id="@+id/main.collapsing"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                app:layout_scrollFlags="scroll|exitUntilCollapsed"
                android:fitsSystemWindows="true"
                app:contentScrim="?attr/colorPrimary"
                app:expandedTitleMarginStart="48dp"
                app:expandedTitleMarginEnd="64dp">


                <android.support.v7.widget.Toolbar
                    android:id="@+id/toolbar"
                    android:layout_width="match_parent"
                    android:layout_height="?attr/actionBarSize"
                    app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
                    app:layout_collapseMode="pin"/>

            </android.support.design.widget.CollapsingToolbarLayout>

        </android.support.design.widget.AppBarLayout>

        <include layout="@layout/content_scrolling" />


    </android.support.design.widget.CoordinatorLayout>

    <LinearLayout
        android:id="@+id/footer"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:weightSum="5"
        android:background="@color/colorPrimary"
        android:alpha="1"
        android:layout_alignParentBottom="true"
        app:layout_behavior="@string/appbar_scrolling_view_behavior">


        <EditText android:id="@+id/data"
            android:layout_width="0dp"
            android:layout_height="24dp"
            android:hint="Enter data"
            android:paddingLeft="10dp"
            android:background="@null"
            android:layout_marginRight="10dp"
            android:layout_marginLeft="16dp"
            android:lines="1"
            android:layout_weight="3" />

        <Button android:id="@+id/btn_send"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:background="@null"
            android:text="SEND"
            android:textSize="16dp"
            android:textColor="@color/colorPrimary" />

    </LinearLayout>

</RelativeLayout>

content_scrolling.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:layout_behavior="@string/appbar_scrolling_view_behavior">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:paddingBottom="0dp"
        android:scrollbars="vertical" />
</RelativeLayout>

ScrollingActivity.java

public class ScrollingActivity extends AppCompatActivity {

    private RecyclerView recyclerView;
    private MyAdapter mAdapter;
    private ArrayList<Card> arrayList;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_scrolling);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
        arrayList = new ArrayList<>();
        mAdapter = new MyAdapter(this, arrayList);
        LinearLayoutManager layoutManager = new LinearLayoutManager(this);
        layoutManager.setStackFromEnd(true);
        recyclerView.setLayoutManager(layoutManager);
        recyclerView.setItemAnimator(new DefaultItemAnimator());
        recyclerView.setAdapter(mAdapter);
    }

    @Override
    protected void onResume() {
        super.onResume();
        for(int i=0;i<60;++i) {
            arrayList.add(new Card("TEXT "+i));
        }
        mAdapter.notifyDataSetChanged();
        if (mAdapter.getItemCount() > 1) {
            ((LinearLayoutManager)recyclerView.getLayoutManager()).setStackFromEnd(true);
            recyclerView.getLayoutManager().smoothScrollToPosition(recyclerView, null, mAdapter.getItemCount() - 1);
            //recyclerView.scrollToPosition(mAdapter.getItemCount()-1);
        }
    }        
}

Now there are 3 problems

1. RecyclerView is not scrolled to bottom though I tried different options such as stackFromEnd and smoothScrollToPosition

   1.1

2. Keeping the appbar in expanded mode, if you tap on the EditText, Toolbar is not collapsed, instead it just scrolls up, but a portion of toolbar is visible as header

   2.1

3. Keeping the appbar in collapsed mode, on tap of EditText scrolls the toolbar to top and is not visible.

   3.1