The forum is public to everybody.
We do not have create a specific forum for the customers.
Concerning the procedure to get the latest versino.
You have to click on the check box to get the new version download ID or you will recieve your current version download ID.
See the FAQ where a video explain how to get the latest.
We perhaps will add message to be more explicit in this webpage.
www.jms2win.com/faq#sec-122
Yes you can also share the user when they are located into different DB.
This just need a MySQL user that has the permission to access both DBs.
Concerning the Single Sign-In, I remember you something that is documented in the product detail, this works on the same domain. That mean that you can have slave site in subdomains or subdirectories. When you have different domain, you can share the users but the session will be different and therefore the users will have to relogin with the same login and password.