Hi and thanks a lot for offering advice.
I place the main FB pixel in the header.tpl file just above the </head> tag. And I use the {literal} tags as well. Otherwise it doesn't work...
Something like this...
<!-- Facebook Pixel Code xxxxxxxxxxx-->
<script> {literal}
!function(f,b,e,v,n,t,s){if(f.fbq)return;n=f.fbq=function(){n.callMethod?
n.callMethod.apply(n,arguments):n.queue.push(arguments)};if(!f._fbq)f._fbq=n;
n.push=n;n.loaded=!0;n.version='2.0';n.queue=[];t=b.createElement(e);t.async=!0;
t.src=v;s=b.getElementsByTagName(e)[0];s.parentNode.insertBefore(t,s)}(window,
document,'script','//connect.facebook.net/en_US/fbevents.js');
fbq('init', 'xxxxxxxxxxxxx');
fbq('track', 'PageView');
</script>
<noscript><img height="1" width="1" style="display:none"
src="https://www.facebook.com/tr?id=1489521851260392&ev=PageView&noscript=1"
/>{/literal}</noscript>
<!-- End Facebook Pixel Code -->
</head>
<body{if isset($page_name)............... and the rest follows
This is the header part which registers "PageView" events for the whole site. In other words every page on your site.
Then I place the other event specific snippets in the relevant pages for the events you want to track.
For conversion the snippet:
<script>{literal}
fbq('track', 'Purchase', {value: '5.55', currency: 'USD'});
{/literal}</script>
on the order-confirmation.tpl file.
And the "View"Content" snippet on the produc.tpl file. This event tracks product page views only.
I test them all with the FB Pixel Helper extension on Chrome. This shows that it works.
Like this for the AddToCart pixel.
http://screencast.com/t/04B4NfuuU2
-------> Except the Checkout pixel never fires when I do a PayPal Europe checkout. It fires when you use other modules like Check payments, etc. And the reason is that the order-confirmation page is not called in my setup. I tried all the different options like express checkout, 5 step v. one page checkout. etc...
I received confirmation from other people that their PayPal Europe module calls the order-confirmation page at completion of payment.
But in my setup it never reaches the order-confirmation page. Here is my proof:
http://screencast.com/t/d8hIUDOqZ4SV
So my conclusion is that the pixel placement as explained by all above works provided the page you place it on is called by the event you want to track.
I hope this can save some people some time.