WP Libra

I would go through http://codex.wordpress.org/Changing_File_Permissions

Then you need to go through your posts/template/pages ect and change your pictures to your new URL if you migrated the images over.

If it works on categories but not the homepage then you need to take the HTML layout on categories.php and match it up with the homepage template.

Maybe try something like http://wordpress.org/extend/plugins/better-delete-revision/

Only thing I can guess (if you go to screen options and select revisions) is you might have a revision that is save with a future date. How that would happen, I dont know.

But try running something like that plugin. Just beware it will clear all revisions for all your posts.

Did you ever publish it? Preview and publish are different.

Make a post. Publish it.

See what your permalink is.

Delete post. Trash it.

Make the exact same post and it will use the same permalink.

Users meaning authors? Make an author.php template

http://codex.wordpress.org/Author_Templates

Can use something like

<?php
if ( is_user_logged_in() ) {
    echo 'Show the button';
} else {
    echo 'Dont show the button';
}
?>

Looks like the images are coming from the below plugin

http://wordpress.org/extend/plugins/coin-slider-4-wp/

So find Coin Slider option page in wp-admin.

.wrapper {
    margin: auto;
    position: inherit;
    width: 1100px;
    z-index: 0;
}

Remove the position line.

So the z-index and position line only. Not the background.

I only checked on homepage so it might up inner pages. So test after you change it.