Please try the steps below to disable  “Open with report  Builder”
1. Connect to reporting  services server and open  reporting services  configuration manager.
2. Go to database setup and note Database Server name and database name.
3. Open management studio on any workstation and connect to the database server from previous step.
4. Expand database node then expand tables, you will see table named “ConfigurationInfo”. Right click and go to Edit table, this will return all the rows from the table. You will see three columns: “ConfigInfoId”, “Name” and “Value”.
5. We need to search for “EnableReportDesignClientDownload” and make the value to “False” to disable “Open with Report Builder”

Regarding diable “Subscribe” option, you need to remove the create alerts and manage alert permission from the user. Below is the way to customize “view only” permission in order to disable “Subscribe” button for your reference.
1. Go to “Site setting” -> “User and Permissions” -> “Advanced Permission” -> “Settings” -> “Permission Levels”
2. There is a permission level named “view only”. By default “view only” permission level doesn't have “add items” and “edit items” permission. Add the two permissions “add items” and “edit items” and uncheck “create Alerts”
3. Click “submit”
4. Give the new “View only” permission to the users you want. Now when they access the page, they should see the “subscribe” option  disabled.