You can do both of those by editing the template postbit_legacy. Find the code that looks like this:
Code:
<span class="usertitle">
{vb:raw post.usertitle}
</span>
<vb:if condition="$post['rank']">
<span class="rank">{vb:raw post.rank}</span>
</vb:if>
{vb:raw template_hook.postbit_userinfo_left}
and remove the part in red. Then farther down, find the code that looks like this (joindate), and add the code in red:
Code:
<dl class="userinfo_extra">
<vb:if condition="$post['rank']"><dt>Rank</dt> <dd>{vb:raw post.rank}</dd></vb:if>
<vb:if condition="$post['joindate']"><dt>{vb:rawphrase join_date}</dt> <dd>{vb:raw post.joindate}</dd></vb:if>
If you want, you can create a phrase with type GLOBAL that says "Rank" and use that instead of putting the word Rank in the template.
For the username color, you can go to the Usergroup Manager, edit each group, and enter Username HTML Markup for the group. For example, you could make a group red by entering <span style="color:red"> and </span> for the two markup boxes. (Click on the "Help" icon next to Username HTML Markup for more examples).