I would submit that from a safety point of view, pending further research, snus and WTA e-liquid can be considered much of a muchness.
The difference would be the nicotine content - some snus is POWERFUL, and you'd really have to be on a mission to hit those nicotine levels vaping. Of course, you don't have to buy the powerful stuff.
I think any ex smoker knows how insidious tobacco addiction is, and they're not going to try snus and suddenly get unwittingly sucked into a whirlwind addiction. If you're regularly using several pieces a day, you know what you're risking (although obviously the safety profile isn't even remotely similar), and you need to pay attention.
If you use it on a plane, I'd see it to all intents and purposes as 'more effective and pleasant gum*'.
* Chewing optional
