Welcome to OpenSprinkler!
In regard to the firmware version, you may find this in the about page which is accessed via the side panel (top left icon).
The automatic DST adjustments are only available in firmware 2.1.0, so please upgrade your firmware. For assistance with this please refer to our guide: https://opensprinkler.freshdesk.com/support/solutions/articles/5000123042-how-to-upgrade-opensprinkler
The manual is current for v2.2u hardware however the guides are not completely updated for 2.1.0 but should be updated soon.
The master valve can be enabled in the edit options page. Once a master station is selected for use, you may use the edit stations page to select which stations require a master valve.
The end time setting is being phased out and I recommend you upgrade to firmware 2.1.0 as it greatly simplified this process and adds a lot more options including per-station watering times.
Hope this helps!