The links in Preview mode should not be opened at all or at least opened automatically in a new window, so that user could preserve its content.

Possible resolution is to invoke the setTargetsForPreview method on the OnClientLoad event of the editor:

<telerik:RadEditor runat="server" ID="RadEditor1"
	 EditModes="Preview" OnClientLoad="OnClientLoad">
	<Content>
		<a href="http://www.telerik.com">Link</a>
	</Content>
</telerik:RadEditor>

<script type="text/javascript">
	function OnClientLoad(editor, args) {
		Telerik.Web.UI.Editor.Utils.setTargetsForPreview(editor);
	}
</script>

Navigate to:

http://localdemos.telerik.com/aspnet-ajax/treelist/examples/databinding/loadondemand/defaultcs.aspx

1) Expand item with ID:2, then items: id:1413, id:1414

2)Expand item id:1

3)Fill Item ID textbox with "303" and Level textbox with "2"

4)Click "ExpandItemToLevel"

5)The icon of item 304 seems like "expanded"(and it should be), however the item is not expanded.

RadScheduler's "today" link is positioned below the Prev/Next arrows in Safari on iOS and OS X.
It is positioned properly after changing the views.

As a quick fix, you can set CSS:
    <style type="text/css">
        html .RadScheduler .rsHeader > p {
            width: 80px;
        }
    </style>

Width value will vary depending on the skin used.

There is a missing label in the Box tab (Width and Height options) in the StyleBuilder dialog.

You can dynamically change the label by following this example:

<telerik:RadEditor runat="server" ID="RadEditor1" OnClientCommandExecuted="OnClientCommandExecuted">
    <Tools>
        <telerik:EditorToolGroup>
            <telerik:EditorTool Name="StyleBuilder" />
        </telerik:EditorToolGroup>
    </Tools>
</telerik:RadEditor>

<script>
    function OnClientCommandExecuted(sender, args) {
        var command = args.get_commandName();

        if (command === "StyleBuilder") {
            var dialog = sender.get_dialogOpener()._dialogContainers[command];

            dialog.add_pageLoad(fixSectionName);
        }
    }

    function fixSectionName(sender, args) {
        var dialogWin = sender.get_contentFrame().contentWindow;
        var label = dialogWin.$telerik.$(".reStyleBuilderBoxSize").find("legend");
        label.html("Dimensions");
    }
</script>

RadSpreadSheet control that can open and visualize excel files. It should also support edit and common operations.

For the time being you can use the following workaround:

CSS:
	<style>
		.RadForm_Bootstrap.RadForm.rfdButton form a.rfdSkinnedButton {
			padding: 0px;
			height: 32px;
		}
			.RadForm_Bootstrap.RadForm.rfdButton form a.rfdSkinnedButton input.rfdDecorated {
				height: 32px;
			}
	</style>

ASPX:
		<telerik:RadScriptManager ID="RadScriptManager1" runat="server"></telerik:RadScriptManager>
		<telerik:RadSkinManager ID="RadSkinManager1" runat="server" Skin="Bootstrap" ShowChooser="true"></telerik:RadSkinManager>
		<telerik:RadFormDecorator ID="RadFormDecorator1" runat="server" DecoratedControls="All" />
		<asp:Button ID="Button1" Text="Click" runat="server" />

This leads to possibility for the end-user to press the button before selecting the content area and accept/reject tracked content. 

This can be resolved via some custom code that disables the tools on initial load. For example:

<telerik:RadEditor runat="server" ID="RadEditor1" OnClientLoad="OnClientLoad"
    EnableTrackChanges="true" TrackChangesSettings-CanAcceptTrackChanges="false">
    <Tools>
        <telerik:EditorToolGroup>
            <telerik:EditorTool Name="AcceptTrackChange" Text="Accept Track Change" />
            <telerik:EditorTool Name="RejectTrackChange" Text="Reject Track Change" />
            <telerik:EditorTool Name="AcceptAllTrackChanges" Text="Accept All Track Changes" />
            <telerik:EditorTool Name="RejectAllTrackChanges" Text="Reject All Track Changes" />
            <telerik:EditorTool Name="EnableTrackChangesOverride" Text="Enable Track Changes Override" />
        </telerik:EditorToolGroup>
    </Tools>
</telerik:RadEditor>

<script type="text/javascript">
    function OnClientLoad(sender, args) {
        var editor = sender;
        var toolNamesToDisable = ["AcceptTrackChange", "RejectTrackChange",
            "AcceptAllTrackChanges", "RejectAllTrackChanges"];
        var canAcceptChanges = editor.get_canAcceptTrackChanges();

        if (!canAcceptChanges) {
            for (var i = 0; i < toolNamesToDisable.length; i++) {
                var toolName = toolNamesToDisable[i];
                editor.getToolByName(toolName)
                    .setState(Telerik.Web.UI.Editor.CommandStates.Disabled)
            }
        }
    }
</script>

Using the RadEditor with Auto or Mobile mode in a RadWindow is impossible because JS error are thrown when dialog is shown. 

For the time being, the most proper solution for this case is using the Lightweight mode for RadEditor.

The NuGet packages should not install directories into the project. If these directories are not needed when referencing the dlls traditionally, I can't see why they are needed with the Nuget package. Adding nuget references to ASP.Net AJAX in a non-website/application project results in a silly set of directories. Like, if you want to write a plain assembly that simply uses the Telerik controls in a Server Control.

An install.pl file should handle any web.config alteration on install.

The 

http://demos.telerik.com/aspnet-ajax/editor/mobile-examples/overview/default.aspx

Error: Uncaught TypeError: Cannot read property 'Polling' of undefined

When adding a link with a class name, the Unlink command cannot remove the formatting. 

Temporary solution is to clear anchor's classes programmatically via the ApplyClass command:

<telerik:RadEditor runat="server" ID="RadEditor1" OnClientCommandExecuting="OnClientCommandExecuting">
    <Content>
        <a href="http://www.telerik.com" class="my-class">link</a>
    </Content>
</telerik:RadEditor>

<script type="text/javascript">
    function OnClientCommandExecuting(sender, args) {
        var command = args.get_commandName && args.get_commandName();

        if (command === "Unlink") {
            var myArgs = new Telerik.Web.UI.EditorCommandEventArgs("ApplyClass", null, "");
            sender.fire("ApplyClass", myArgs);
        }
    }
</script>