1) What do you mean by "no folders" customization.
Do you mean the the JMS Templates "folders and files" tabs does not appear ?
2) If you have a blank screen as you could read plenty of times in this forum, this is the symptom of a PHP fatal error somewhere.
So you have to check your server error log to get more info.
This might be due to permission error on your server.
3) Same as (2)
If you want that we have a look on your server or help you to setup your environment or teaching you, this is also possible with our billable support that you can order at
www.jms2win.com/en/joomla-multisite?page...35&category_id=1