User Manual Kwikset 99120-037 Tustin Lever Electronic Keyless Entry Deadbolt

The lock will stay unlocked until you send a lock command. However I think there is a relock feature on the lock itself but , I haven’t used it to know.

To the best of my knowledge, you can turn the auto-lock option off.

You can use the lock as a code only device but they do make one that doesn't have the Z-Wave and still has the keypad.

No I use mine with wink hub

I was able to add codes to the lock using my smartphone and Smarthings hub. It also appears to let you change codes that have been added manually, but i have not had to do this yet.

Haven’t tried. I use wink hub

You can but it can be a little flakey at times... doesn't always work. I am running micasaverde device to control a wave devices.

Depends on usage. I have medium usage on mine and normally 4 to 8 months with good quality batteries. My low usage ones locks last 6-8 months

Yes they do. I have bought 2 and they both have worked