sebyku on "Facebook conflict on my wordpress"

On my wordpress website I have a lot of facebook interactions like og.watch, fb.login and others. For example I use:

http://w.sharethis.com/button/buttons.js

for some buttons and this js include all.js from facebook. This is in head.

Again in head I have:

<script type="text/javascript">
    window.fbAsyncInit = function(){
        FB.init({
            appId: xxxxxxxxxx,
            status:true,
            cookie:true,
            xfbml:true,
            oauth:true
        });
    };
</script>
<div id="fb-root"></div>
<script type="text/javascript">
// Load the SDK Asynchronously
  (function(d){
     var js, id = 'facebook-jssdk', ref = d.getElementsByTagName('script')[0];
     if (d.getElementById(id)) {return;}
     js = d.createElement('script'); js.id = id; js.async = true;
     js.src = "//connect.facebook.net/ro_RO/all.js";
     ref.parentNode.insertBefore(js, ref);
   }(document));
</script>

And in footer I have fb-like-popup.js from a plugin witch use fb.edge to verify a like button.

The main problem is that sometimes I get in the console errors like: Fb.init not defined in fb-like-popup.js and when I have this error in the page I cannot use the facebook features from my page.

Question 1: Why do I get in different files fb.init not defined while I have the fb.init in the head of page?

Question 2: Is there a method to define facebook once for all my site pages?