I can't think of anything to worry about in this regard. You can connect and test the the unit without actually attaching to your solenoids. If there was an issue with the hardware controlling the solenoids it would be under warranty.
Yes! Manual controls
We've built a custom enclosure if you need it installed outside, the device does have a current sensor that will allow us to detect faulty zones (software TBD), some fun new LEDs, and the gen2 hardware will allow it to integrate with other platforms in the future that the gen 1 is not possible to do.
Hope this helps.