Chances are the payment hasn't cleared at the sellers end, PayPal often hang onto money for up to 3 or 4 weeks as a security measure (especially for new sellers) BUT that isn't your problem, the seller should still dispatch straight away, this will have been detailed in the email they received confirming your payment. They certainly shouldn't be waiting until the payment is released at their end.
I'd send them another email informing them of this, and tell them if you don't have a tracking number within 24 hours, then you will have to open a not received dispute with ebay. If you don't get one then open one.
If you do open a dispute, then ebay will give the seller 7 days to resolve the issue before you can escalate for a refund, so best try to sort it out with the seller first, if it means you will get your item quicker.
If you're going to leave non positive FB, wait until you have your item or refund, then leave it. And keep it factual.
smiling you're correct, sellers aren't supposed to sell "e-cigs", as such, but they are allowed to sell vape kits, as long as they don't contain nicotine.