Seems worse than drinking non-alcoholic beer, and not as bad as getting addicted to actual nicotine.
Many Christians even debate with themselves if actual smoking is a sin, I attest that it is. Not only is relying on a chemical instead of God or a healthy activity a rejection of God, but the very act of "maintaining" or engaging in the behavior over and over becoming fixated on it is also unhealthy and an ignorance of God.
But it's nicotine free?
Inhaling "vape" is bad for your lungs and body, doesn't matter than it's "not so bad" or "as bad", you are still choosing to engage in an unhealthy act to cope with reality or distract yourself from reality or "amplify" reality, depending on your reasoning/excuse for doing so.
And your vape is going to put you around people using nicotine and other "stuff" in their vapes, wait until they pass you there "e-cig" and you get a couple puffs out of their magic electronic dragon. You hold in your hand a nicotine-free electronic gateway to drugs!
I'm not physically addicted or crave it or anything.
It's can become a "fixation", crutch, activity you do or feel like doing to disengage or feel comfortable socially. You're using your e-cig to increase your enjoyment instead of God, and you may even have the vape on the mind distracting you from healthy thoughts. I worked with people who took periodic smoke breaks to do the e-cig like you without any of the blatant poison in it, it can become a fixation or habit, which isn't a good one in this case.
I start and quit smoking "real" tobacco multiple times a year (currently I do not), and drink 4-5 alcoholic beverages as a social crutch or to cope with reality by myself, I guess a couple times a month I do this. I drank two bottles of wine on Tuesday and also Wednesday. I'm not a saint telling you that I'm better than you or that your actions are a definite ticket to hell.
I know when I do these things it's a sin, I feel guilty about it, I repent, I ask God to help me stop and to fight the urges when I have them. I recognize the sins for what they are, that's all I want you to do.