Started casting when I was 11 with my Uncle. One thing I like about my cast iron pot is that it has a lid!!! I try and dry tire weights as much as possible but even in the clip area salt can pop too!!!!
Don't know why folks smoke their molds I've never had to do it, and I cast alot. Split shot and any sinker less than 1/2oz. in Vermont have to be tin/non-lead, the split shot are a pain to pour in tin but I haven't tried the sinkers yet, with pouring jigs they're just cheaper to buy. If you're worried about any type of grime or any lead popping you can get a pizza pan to set on top when your weights start to melt, just a little extra protection.