Since there is no use besides interacting with stick man health. This is most likely a mod element.
Also lead with acid or caus trying to dissolve it get absorbed by the lead to produce a spark.
Lead acid battery.
No,it's a suggestion for a new element.
I can see one significant reason to make LEAD. Make it able to block WIFI signals. if you made a device that uses WIFI and surrounded it in LEAD, those WIFI signals would be intrinsic to that device. this would prevent wifi cross talk with devices that use the same channels.