The part of the issue where the title bar overlaps the taskbar will be declined. 

Setting the WindowsState property with code in the form`s constructor to Maximized and at the same time, the MaximizeBox property of the form to false is not valid. The same behavior can be observed with the standard Microsoft form which will also overlap the taskbar. It is not intended to maximize the form if its MaximizeBox property is set to false, with this setup the end users is restricted and they have no UI to maximize the form. It is possible to set maximize it programmatically, however, this may lead to some undesired behavior. Yet, in the discussed scenario the form can be maximized initially if the WindowState and MaximizeBox properties are set in the Shown event:

private void RadForm1_Shown(object sender, EventArgs e)
{
    this.WindowState = System.Windows.Forms.FormWindowState.Maximized;
    this.MinimizeBox = false;
    this.MaximizeBox = false;
}

The issue with the cut off text is logged as new on the feedback portal, here: https://feedback.telerik.com/winforms/1406413-radform-the-text-of-the-form-is-cut-off-on-the-left-side-if-the-form-is-maximized-and-the-icon-is-not-visible