I once spilt 72mg/ml nicotine all over my hand while mixing (it was dripping off me), I waited a good 10mins before wiping it off with some kitchen towel, I had a mix to finish! Long story short, nothing happened. I felt perfectly fine, I didn’t die, I don’t think but the proper way is the way to go, like others have suggested, had it gone in my eyes I would have been panicking all the way to the fridge to get another beer before I was permanently blinded but a little bit of nic on the hand is worth 2 in a bush or something…
I guess what I’m trying to say is, be wary but don’t be over cautious or nervous using nicotine as that can cause its own set of problems.
As for storage, I keep my bottle in a sealable bag in the kitchen medicine cupboard, I’ve had no issues with it going bad.
Oh, I dispense mine with a 1ml throw away pipette