Can you create a subscription in SQL Server Reporting Services to deliver to Public folder?

Public folder is shared by all the users of a computer and you should have no problem creating a subscription to deliver to the Public folder. Provide the UNC path to the folder.

Here is a subscription.

This subscription delivered a report to the Public folder.

How do you add Full-Text feature to an existing installation of SQL Server 2016 SP1?

It is a good practice that you only install what you need, otherwise you may end of reserving resources for things you do not need. However often times you need to add a feature to an existing installation of SQL Server 2016. There is no better place to go than the SQL Server Installation Center. This slide show shows how you may do this.

https://youtu.be/6S25lHM15E4