I can help you make those changes.
The first thing you’ll need to do – if you haven’t already – is set up a child theme, so your tweaks won’t be overwritten when updating the theme. Here are some guides in case you haven’t made one before:
http://codex.ww.wp.xz.cn/Child_Themes
http://op111.net/53/
http://vimeo.com/39023468
The author’s name in Dusk to Dawn is displayed on the blog index only when there are published posts by more than one author. To override this default behaviour, add this CSS to your child theme’s stylesheet.
.single-author .entry-meta .byline {
display: inherit;
}
I’ll reply separately about adding the time.
Adding the time to the date on the blog index is a little tricker, since it’s done via a function. Here are the steps:
1) Add this to your child theme’s functions.php file. If your child theme already has a functions.php file, omit the opening <?php tag and just add everything else.
<?php
function dusktodawn_posted_on_with_time() {
printf( __( '<a href="%1$s" title="%2$s" rel="bookmark"><time class="entry-date" datetime="%3$s" pubdate>%4$s</time></a> at <span class="time">%2$s </span><span class="byline"> <span class="sep"> by </span> <span class="author vcard"><a class="url fn n" href="%5$s" title="%6$s" rel="author">%7$s</a></span></span>', 'dusktodawn' ),
esc_url( get_permalink() ),
esc_attr( get_the_time() ),
esc_attr( get_the_date( 'c' ) ),
esc_html( get_the_date() ),
esc_url( get_author_posts_url( get_the_author_meta( 'ID' ) ) ),
esc_attr( sprintf( __( 'View all posts by %s', 'dusktodawn' ), get_the_author() ) ),
esc_html( get_the_author() )
);
}
2) Create a copy of content.php from your parent theme and place it in the child folder. Change this line:
<?php dusktodawn_posted_on(); ?>
to this, to call in your newly modified function which displays the time:
<?php dusktodawn_posted_on_with_time(); ?>
This is what it looks like on a standard post:

Note that the time will also be added to the date on single posts as well, because they both use the same function.
Edit: I change the word “on” to “at” in the function as that makes more sense with the time.
Thank you so much for your answers! I’m off to try and implement them right now. π