I've been casting bullets since '76. Muzzleloader round balls since then (thousands and thousands), and my own alloy mixed bullets for B.P.C.R. since '99 (20:1 lead/tin). About 20 years ago, I had my blood tested for heavy metals, and literally nothing showed up in my test as far as regarding anything harmful running through my blood. Now, all my casting is done in front of a sliding garage window, with two, stacked, heavy duty floor fans drawing anything fume-wise from the pot. I can see any vapors, smoke or any mirage looking "essence" all heading to the fans and out the window. It works very well for me, and I'm good with it. I'm 69, and now, to me, good ventilation is an absolute must when casting these days. I'm good with my system.
BTW, your system looks very good for the business. Have fun makin' pills! One other thing; WASH YOUR HANDS (even after taking off the casting mitts) anytime you leave your station. Our house has the laundry room right off the garage when walking into the living quarters. I stop and wash my hands anytime I pass through there during a casting session.