The text "Welcome" can be entered in the module configuration, you need only change it. It is the "Pre-Text" configuration. For the messages, change the following code around line 154:
<td><a href="', sefRelToAbs($str_jsmf_url . "action=pm") ,'" class="',(($moduleclass_sfx) ? 'mainlevel'.$moduleclass_sfx : 'mainlevel' ),'">Messages (',$context['user']['messages'],'/<font color="#FF0000">',$context['user']['unread_messages'],'</font>)</a></td>
in that code change the text "Messages" to fit what you want.