Balsa is a really thermally stable hard wood, but it is soft, so I would use a hard epoxy (glue epoxy) like D2T, or a UV cured resin, to protect it.
I seal with runny super glue, paint, and then clear coat with UV cured resin.
I've used a 15 year old version of this vise for jigs and spinnerbaits with hooks to 5/0, and all it does is work:
https://www.basspro.com/shop/en/supreme-rotating-fly-tying-vise
I have only seen them for dust, and the intake was on a belt mounted power pack and filter. But that was 20+ years ago.
You can check a woodworking supply store like Rockler to see what's available now:
http://www.rockler.com/search/go?w=dust masks
In order for a mask that filters organic vapors to work, it has to have the proper organic vapor filter with a large capacity, and a fan system to deliver the clean air.
Maybe Grainger's would carry that kind of mask.
This is a quote from TW's Roboworm site:
"The super soft plastic Strait Tail Worms end up having a very sensitive, alluring action complete with a Salt Release System that provides a burst of salt when a fish bites ' causing them to hold on longer for solid hooksets."
A MAC valve just before your air brush lets you change and control the air pressure easily:
http://www.coastairbrush.com/proddetail.asp?prod=Iwata_Mac_Air_Controll_Valve
I have one just before my quick disconnect fitting, so it stays on the air line no matter which brush I'm using.
Personally, I think Baitjunky's right.
The challenge of making my own plastisol, no matter how rewarding it might be, isn't worth the time and trouble it would take.
Of course, if you can't get it where you live, then that might be another story.
Do you print halves and then do all the ballasting and hardware installation yourself first, or do you send them the prototype body and let them do that stuff?
Try putting some clear nail polish over the hook rash areas. That stuff is tough.
After I've painted a bait, and top coated it with Rustoleum X2 Gloss Clear, I put a coat of nail polish over the path of the trebles, and don't get hook rash.
But I don't paint trolling lures, so I don't know how it would hold up to trolling.