Automatic read more so Annoying!

Hello,

I’m using TheGamer template on my wordpress.
http://newwpthemes.com/thegame-free-wordpress-theme/

But I have one thing I would like to change.

When I create a post, it appears on main page, which is OK.
But it will automatically cut and show button READ MORE.

I don’t want to cut it.

I have tried replacing in post.php of theme
echo $theme->shorten(get_the_excerpt(), '40');
with
echo get_the_excerpt();

but it doesn’t work as intented, because:

1. It shows READ MORE even if the whole post is shown on main page
2. Sometimes it doesn’t show the whole post (few last words missing)
3. The shortened version of post on main page is missing all line breaks etc…

What I want:
1. Cut the post and show READ MORE ONLY if I use <!–more–> tag
2. If I don’t use <!–more–> tag I need to show the whole post on main page
3. I want the post to show with all line breaks etc… just like in full view.

Please can someone help me? You are mine last hope.