You can also use rubbing alcohol, it’s actually what bountiful baby recommends in their tutorials. Doesn’t solve the baking fumes issue but definitely the thinner fumes. I’ve used it before and I can’t say I like it as much as odorless spirits but it worked well. It’s just a little thinner feeling, more watery less oily if that makes sense, it’s hard to explain the difference really 
Yes, you can. The more layers you apply, the more it does add some texture you can feel. Not gritty like matte varnish but thickness to the paints. If you work the paint well on your pallet so that it becomes more fluid like then it is easier to apply it more thinly to the vinyl. I like to use it when painting AA skin tones because it gives a more smooth look. If you have ever used any of the Secrist pre-mixed colors that you can use straight from the jar that is what they are, Genesis paint mixed with Genesis thinners. I admit there is still advantages to using the odorless thinners overall but that is why I recommended the Zest-It. I have a high sensitivity to the odorless thinners, which is why I switched to air dry paints mostly. However, I did find painting with Zest-It worked for me but I just had to order it off Ebay and wait for it to get here as it seems hard to get in the USA.
Really wow I have never heard of that. Thanks for the suggestion
Ok thank you so much I will look into my options