Hi gll1559,

To disable the fullscreen button, please set  DisabledItems="fullscreen".

 <RTE:Editor ID="editor1" runat="server"   DisabledItems="fullscreen" /> 

To hide the preview tab, pleaset set ShowPreviewMode="False".

<RTE:Editor ID="editor1" runat="server"  ShowPreviewMode="False"/> 

Regards,

Ken