...Is it true that 1 drop of 100mg nic on the skin can take you out?
Unlikely for an adult that has nicotine tolerance. Get a drop in your eye and you may wish it would though. There is a lethal range and it is measured in mg/kg typically, so the bigger you are the more it takes and the reason to make sure pets and children are no where near the stuff.
I work with 100mg at my mixing table. Doesn't get hot enough in Indiana to make fumes any sort of issue so it's pretty straightforward for PPE and typical proceedures.