gallery shortcode no alt tag and script inside body tag

if I’m using the new gallery shortcode validator shows me more than one error ??

document type does not allow element “style” here.

<style type='text/css'>

and there is no alt atrribute

wp-includes/media.php

function get_image_tag – I found this function and I see that there is an alt attribute but it doesn’t work

and one br has no slash – so it is invalide

line 412

$output .= "
<br style='clear: both;' >
</div>\n";

and is there a way to send the style between head and /head and not into body tag –

thanks a lot

Monika