Setting escaped symbols in the text nodes of the content breaks cursor navigation and word deleting.

This is due to IE10 and less browser versions native behavior to interact with escaped symbols as normal ones. 

A possible resolutions is implementing a filter that strips the undesired characters and disable the IndentHTMLContent:

ASP.NET
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<telerik:RadEditor ID="radEditMain" runat="server"
     EnableTrackChanges="true"
    OnClientLoad="OnClientLoad">
</telerik:RadEditor>

<script type="text/javascript">
    function OnClientLoad(editor, args) {
        editor.get_filtersManager().add(new MyFilter());

        var cleanHtml = editor.get_html(true);
        editor.set_html(cleanHtml);
    }

    MyFilter = function () {
        MyFilter.initializeBase(this);
        this.set_isDom(false);
        this.set_enabled(true);
        this.set_name("MyFilter");
        this.set_description("RadEditor filter description");
    }

    MyFilter.prototype = {
        getHtmlContent: function (content) {
            var newContent = content;
            //Make changes to the content and return it
            newContent = newContent.replace(/(\r\n|\n|\r)/gm, " ");
            newContent = newContent.replace(/(\t)/gm, " ");
            return newContent;
        }
    }
    MyFilter.registerClass('MyFilter', Telerik.Web.UI.Editor.Filter);
</script>
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C#
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protected void Page_Load(object sender, EventArgs e)
{
	radEditMain.DisableFilter(EditorFilters.IndentHTMLContent);
}
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