WP Tactical Popup

Make sure that you clear your cache (browser side and server side).

Adding an email popup is easy.Click Add Popup and then Add Email popup. In the first tab you will need to paste the form that your email provider supplies you (often called embedded form). This is HTML Code. It will be automatically parsed by the plugin.

Make sure that the header.php file of your theme starts with an HTML5 doctype.

Make sure to clear the cache, delete the cookies and disable any minification plugins. Minifications plugins often cause javascript errors, since they combine all javascript into one file. This changes the relative path and most minification plugins do not take this into account

Yes, the most certainly are if you do not configure them properly. In order to reduce the inconvience to the end-user, some specific settings are recommended. Make sure to show only once in seven days after a minimum of two pageloads. A delay of 7 seconds or more is recommended. This gives the user time to go trough your content. Ultimately this will increase your conversions rates significantly.

Yes, just paste HTML of the Facebook or Twitter buttons inside the HTML field. However, for Facebook you might want to try Facebook Page Promoter Lightbox, which is specialized for this purpose.