The juice is the only thing I can really see them being able to crack down on. As far as hardware goes though, even if they crush our vendors here stateside under their heel, the Chinese have nothing against vaping, and make most of out carto's and are even cranking out RBA's now. If they do anything hardware related it'll pretty much just hurt the US economy, and cause honest people here to lose their businesses and jobs.
Vaping is as big there as it is here, and they lie like crazy on their customs forms. I had a dozen cheap ego's come through labeled as "Flashlights". On the x-ray most of our e-cig stuff looks pretty much like any other tubular electronic you can imagine. The Li-Po and LiMg batts we use are not too much of a worry either, those have never been a PV only power source. You can find em in pretty much any high capacity battery pack out there now, and they are used in almost every modern hand held measuring device and RC plane I've ever used. So those are not going anywhere.
Our PG and VG are also fairly safe, as mentioned before, those are used in other industries as well. PG is wide spread as a food additive, and already on the safe list of crap that the FDA already approved. Just pick up and read the ingredients on some of you food packages, you'll find it listed on a lot of them. Also it's the base for most smoke machines to make the SFX smoke, and used in most aerosol based RX inhalers as the carrier for the medication. VG also has it's place as mentioned earlier in the lotion, soap, and candle industries. Both are USP cert base chem you can buy in bulk if you know where to look.
Also the kanthal and Nichrome wire used in RBA's is pretty much a standard heating wire used in your toasters, dryers, and heaters, so we'll still have that along with the silica, SS mesh, and cotton used as wicking. So on the hardware side, I'd say we'd still be able to manage, though it will be a royal PITA having to wait weeks for crap from China instead of days, or a quick trip to the local vape shop.
Also, our flavors will still be available, and pretty easy to get, after all most of what we use to flavor our juice is just standard food flavoring. They couldn't really clamp down on that without hurting every bakery, cake shop, and confectionery producer in the country, and lets face it we love our sweets too much here in the US for THAT to happen. You saw the ruckus that was kicked up when Hostess bit the dust.
Our juice is the only real weak point they can put the thumb screws on, so that's what it seems like they are attempting to do. Most of what we use is too deeply entrenched in other larger industries for them to touch. Hopefully they fall flat on their face again, and we can rally in our own defense, but per my normal modus operandi I'm hoping for the best, preparing for the worst and stocking up on the high concentrate nic while I can. We'll wait and see what happens, it's not the first time the FDA has tried their crap and I can bet it won't be the last if they fall short again.