Hmm this seems like you should be able to achieve this, what is is though is the location of the variables in the template itself... one sec let me check... (will edit post once I do brb)
Edit: Ok so yes like I was thinking just location of code in template, it should be so simple as:
AdminCP > Styles & Templates > Style Manager > *Edit Templates of style in question > *Scroll to find "Registration Templates >>" and double-click to open that template "family" > *Now double-click to edit the template
register and find:
Code:
{vb:raw customfields_other}
^ CUT that code from the template, now scroll back up to where you see the username code in the template which will look like:
Code:
<div class="section">
<div class="blockrow">
<label for="regusername">{vb:rawphrase username}:</label>
*Now paste the code as shown:
Code:
<div class="section">
{vb:raw customfields_other}
<div class="blockrow">
<label for="regusername">{vb:rawphrase username}:</label>
And that should move the custom profile fields you have added above the username HOWEVER be advised the titles such as "Additional/Require information" are no longer above the fields so it might look odd simply being FieldName1, 2, 3, 4 then Usertitle so you may want to wrap that customfields var in a div class not sure up to you really

.