Change the link URL in default RSS feeds

You could filter 'the_permalink_rss':

add_filter( 'the_permalink_rss', 'wpse_96602_change_feed_item_url' );

function wpse_96602_change_feed_item_url( $url )
{
    $parts = parse_url( $url );

    return $parts['scheme'] . '://' . $parts['host'] . '/#!view' . $parts['path'];
}

But … I strongly recommend not to do that. Hash-bangs will break your web site.