To disable password change feature, go to the file, /usr/local/cpanel/base/webmail/x3/index.html take backup of the file and remove the below entry,
<cpanelfeature popaccts>
<td >
<div valign="top" align="center">
<a href="mail/passwdpop.html?redirectdomain=&email=<cpanel sprint="$authuser,@,0">&domain=<cpanel print="$CPDATA{'DNS'}">"><img src="<cpanel Branding="image(password)">" border="0" /></a><br><a href="mail/passwdpop.html?redirectdomain=&email=<cpanel sprint="$authuser,@,0">&domain=<cpanel print="$CPDATA{'DNS'}">"><cpanel langprint="ChangePassWebmail"></a>
and to disable mail forward feature, go to the same file and remove the below entry,
<cpanelfeature forwarders>
<td >
<div valign="top" align="center">
<a href="mail/fwds.html"><img src="<cpanel Branding="image(forwardersemail)">" border="0" /></a><br><a href="mail/fwds.html"><cpanel langprint="EAFwdWebmail"></a>
</div>
</td>
</cpanelfeature>
Done
<cpanelfeature popaccts>
<td >
<div valign="top" align="center">
<a href="mail/passwdpop.html?redirectdomain=&email=<cpanel sprint="$authuser,@,0">&domain=<cpanel print="$CPDATA{'DNS'}">"><img src="<cpanel Branding="image(password)">" border="0" /></a><br><a href="mail/passwdpop.html?redirectdomain=&email=<cpanel sprint="$authuser,@,0">&domain=<cpanel print="$CPDATA{'DNS'}">"><cpanel langprint="ChangePassWebmail"></a>
and to disable mail forward feature, go to the same file and remove the below entry,
<cpanelfeature forwarders>
<td >
<div valign="top" align="center">
<a href="mail/fwds.html"><img src="<cpanel Branding="image(forwardersemail)">" border="0" /></a><br><a href="mail/fwds.html"><cpanel langprint="EAFwdWebmail"></a>
</div>
</td>
</cpanelfeature>
Done