2. This thread has some useful information for creating a ratings system, many people have communicated in this thread and said that they were able to use the given code and it works for them, it also helped most of our other clients, please take a look if you find anything useful: https://toolset.com/forums/topic/how-to-get-rating-average-from-cred-for-review/
If above is not sufficient and you would like to do something else using Toolset plugins, It would need some custom coding to make it happen. We have some recommended list of service providers here if you would like to take a look: https://toolset.com/consultant/
You may be able to restrict the users to login by using Toolset Access plugin but it depends on the plugin’s settings as well that if it can be incorporated with Access plugin.
Usually you can show / hide Ratings part or rating stars on a page. And you will place the Ratings Shortcode inside [toolset_access] condition, this will only display ratings options to logged-in users or whichever role you will choose and the general public users can be shown a message to login to leave ratings etc. This condition setup is explained here: https://toolset.com/documentation/user-guides/access-control-texts-inside-page-content/
The above is the only possibility we have at moment. Otherwise to make it more specific and robust solution it would need some custom coding to make it happen. We have some recommended list of service providers here if you would like to take a look: https://toolset.com/consultant/
