Safety first. Gloves which I rarely wear are necessary evils. I always preheat my molds 15 - 20 minutes which IMO prevents a lot of issues including the one you experienced.
I have smoked molds in the past and yes it helps but is messy and I do not like the appearance plus cleaning the soot off of a mold is a Pain In The @ss if you get my drift. I use talcum powder a lot and never had a problem and last fall started using drop out which is a giant leap forward ----- Be sure it is dry, it lasts a long, long time when properly applied.
As far as the spatter getting stuck, first reaction should be turn your hand upside down and dip in water. Although too late now, it helps a lot with the burning. Ideally when you turn your hand over the lead will fall off leaving only a surface burn but it requires a fast reaction on your part. Lead is nasty and loves to stick to skin.
There are gel burn pads that help the healing process and prevent scarring. I discovered them a few years ago when I was welding a contraption and tried to stop it from falling which resulted in a 1-1/2 wide 2-3 degree burn across the back of my hand. Yes it hurt, but the pads led to a rapid healing and were pretty soothing as well.