Probably not much more healthy but I don’t really see how you would be ingesting much more metal from that compared to your metal frying pan for example.
The coil becomes brittle from interacting with the liquid and usually breaks contact when refilling or if dropped. what actually happens is the wick goes bad or burns, and won't "wet" the coil anymore; or you use an e-liquid/e-juice with a lot of sweeteners and the coil gets caked with burnt sweetener and can't fire anymore.
But that's if you're negligent with a DIY or "hand wound" or "drip" vape, where you're using the same coil for a very long time (weeks, depending), and it depends on the liquid, the liquids that taste/smell like bakery/confections absolutely cover coils with gunk that you have to remove the wadding (usually cotton or silicone wicking material, unbleached), and do a dry-fire to burn all the junk off. This smells awful and i usually did it by hanging the thing out a car window and firing it just so i didn't have to smell it. I personally used specialty "wire" that's real thin wire that's twisted to make it thicker, both to make it handle more heat (lower resistance means more voltage can be put in) and last longer, due to less heat stress. 90% of the time when a coil broke for me, it broke where the coil connects to the leg that goes to the terminal block, and rarely the leg would snap at the terminal block instead of the coil, and maybe 2 times the coil broke somewhere along the length. in a little over a decade of use of "rebuildable drip atomizers."
The disposable and pod-based vapes don't have any of these issues because say 9000-18000 "puffs" of 0.5s or longer and you're supposed to dispose of it. With one of the RJR or PMJ vape brands, they're not refillable, so you just throw the pod away; with the "bar" vapes, you throw the whole bar, battery and all, in the trash.
I really advocate for the "refillable pod" and "drip" or "drip tank" vapes, just from an ecological standpoint. Uwell, VodPod(stylized and possibly spelled 'voopoo') make decent pod-based ones, where the device, a pack of 2 pods, and a bottle of e-liquid to fill it with cost about the same as a Vuze device and a 6-pack of pods for the Vuze. And if you're a "heavy user" a 6 pack is < 1 week of vaping; so hands down doing it with your own device and liquid is cheaper, for sure. additionally there's a difference between "mouth to lung" and "Direct to lung" vape devices/pods. MTL is like a cigarette, you draw into your mouth, then inhale into your lungs. DTL is like a hookah or bong, you "breathe" in through the device. I used to prefer DTL but i use MTL now. the vuze and other tiny pod disposable vapes are Mouth to Lung devices.
TL;dr: No. Generally the disposable ones from the two big tobacco companies are "safe" given the GP and your queries. the "bar" ones, like "elf bar" or whatever, i am not sure. There's been QC issues and other reported problems with that type, but they're generally <18000 "puffs" and that, in my opinion that borders on being "dumb". The big vapes you see people using? those are probably safer than even the RJR/PMJ ones, unless the tank is metal. Then you can't be sure, that's up to the user!
Note: the closest thing to vaping prior to vaping was a hookah vis-à-vis nicotine, and a nebulizer, vis-à-vis vaporizing "drugs." They even make things that vaporize marijuana, straight from a grinder, these days. But heating something to create a vapor to inhale isn't "new"!
In fact, the first "e-cig" i ever saw was used by a friend in 2009 or so, and he said it was sold as an "Portable Electronic Hookah". It was a DTL device, with a tank and replaceable wick/coil "cartridge". Most DTL are "replaceable cartridge coil/wick" tanks, and most MTL are "pods"
You are not heating up the atomizer anywhere near that temperature with (2) 18650 cells. Coils are replaced when the cotton that surrounds them gets dirty and the vapor starts tasting bad.
Vaping is (compared to actually smoking tabacco) definitely harm reduction and significantly less harmful (which doesn't mean its healthy and you should do it). Yet it is treated like smoking cigarettes by law. For example in Germany you have to pay tabacco tax on the base liquid (which doesn't even contain nicotine) if it is intended to be used in a vape (17 cents per milliliter) which increased the price of the base liquid from around 10€ to 170€. But the base liquid only consists of two things (propylene glycol and glycerol) and both those substances you can by cheaply in a vet doctors online shop for maybe 5€ each liter. It's ridiculous.
anyhow, i buy juice now, too, but mine was better. I never used sweeteners. My current go-to is Naked Euro Gold 12mg, but i am on the hunt for a 25ml nicotine salt version of a similar flavor. (nicotine salt vs freebase nicotine, salt is more "mellow" and lets you put a higher concentration in, which translates directly to less use, as you're satiated much faster.)
anyhow, as other people and myself said already, the metal never gets hot enough to incandesce, not even remotely close!