Static Pages get "article" tag – can i change it?

Not in the settings. You could use one of the many filters available to remove those meta tags for pages though.

js.

not sure where exactly. are these open features in the free version or just the pro version?

The filters and actions are available in the Free/GPL and Pro versions: https://surniaulula.com/codex/plugins/nextgen-facebook/filters/

js.

not sure where should i implement those?
also can i dfine the og:type as website or blog and not just remove it?

You’ll probably want to hook into the ‘ngfb_og’ filter.

Using WordPress filters is beyond the scope of plugin support, but there are lots of how-tos out there if you google a bit.

Basically, you create a function and hook it into the filter by adding code to your functions.php file. The function you create will receive an array of all Open Graph meta tags — you can then change and/or remove them as you wish.

js.