1. im almost certain that you can fgind one cheaper than 539....(ebay, craigslist, local headshops)
2. solid valve, please
3. 5.5-6 on the dial
4. smell is very minimal and should not be an issue. If you were super paranoid you could vape by a window and be fine

something not mentioned in the post, get the classic volcano. Fuck the digi