Yes, there are some excellent in house creations available. The screensavers have been designed for both business and home PC's and can be found on this page: Screensavers for Windows

The change log is located right here: Screensaver Change Log

Yes, on the main screen look for the auto rotate checkbox, it's right above the Interval seconds  property, make sure that box is NOT checked and auto-rotate will be disabled.  If the box is checked (enabled), it is currently on.

Activate: Sets your configured screensaver as the system screensaver at your scheduled time.

Run: Launches your screensaver at the scheduled time without changing the system screensaver setting.

*Note: When using Auto Rotate, all screensavers in the rotation will use whichever action type you select.

Purpose: When enabled, this option will close any currently running screensaver when your scheduled event begins.