To remove commas, edit the forumhome_subforums template, and remove (or comment out): {vb:raw row.comma}
Alternatively, you can replace the template contents with the following:
Code:
<div class="subforums">
<h4 class="subforumlistlabel">{vb:rawphrase subforums}:</h4>
<ol class="subforumlist commalist">
<vb:each from="subforums" value="row">
<li class="subforum">
<vb:if condition="$row['canpost']">
<img class="inlineimg" src="{vb:stylevar imgdir_statusicon}/{vb:raw row.imageprefix}subforum_{vb:raw row.statusicon}-48.png" alt="" border="0" id="forum_statusicon_{vb:raw row.forumid}" />
<vb:else />
<img class="inlineimg" src="{vb:stylevar imgdir_statusicon}/subforum_{vb:raw row.statusicon}.png" alt="" border="0" id="forum_statusicon_{vb:raw row.forumid}" />
</vb:if>
<a href="{vb:link forum, {vb:raw row}}">{vb:raw row.title}</a>
<!-- {vb:raw row.comma} -->
</li>
</vb:each>
</ol>
</div>