Currently their lifetime is an hour if they don't run out of ammo.
Only the destroyer bots have their health doubled, the other don't. I think they're still quite squishy even with double health, so I don't plan on adding an option to disable that.
The ammo count is basically the way to "balance" this against Vanilla. Basically if an unmodified bot were deployed and were firing non-stop, the number of shots it makes I took as the "ammo count" for this mod. So essentially this mod just helps to make sure your bots are still still alive and haven't timed out when combat starts. However, the actual buffs in combat are fairly limited to just the health and range buff on destroyers. I don't aim to make them OP, just bring them in line with other options.
It should be noted when I made this in 0.16, they were far behind the curve (needing a lot more research and resources to get going, and never felt worth it) - even in vanilla they're in quite a good place now. The tweaks they need are fairly minor IMO.