OP I could have written your post.
My husband and I used to smoke until 4 years ago. We both decided to give up. I went cold turkey and he switched to vaping.
We actually used to both smoke cigars and would never have more than 2, possibly three in a day (not massive cigars - just bit bigger than cigarettes).
Now he vapes - he does it constantly. In the car, in his home office, walking around a theme park, at his desk at work (he has his own office) and he even takes it into the toilet with him.
He never goes more than 2 minutes without a puff on the thing.
He is a "cloudchaser" too ane therefore my entire house stinks of "choconana".
People who think the smell dissipates immediately are a bit mistaken I reckon - either that or my dh vapes so much that the smell never gets the chance to go. He has no less than 30 bottles of the stuff on his desk and is seriously addicted.
He puffs away on it like it is going out of fashion and I am terrified that it will turn out that they are more harmful than we think.
I just can't beleive that it is not harmful to suck a load of wet perfumed steam into your lungs 100s of times a day.
I wish that he would try to vape less - or just vape to replace the cigars we used to smoke - i.e go down to the garage for half an hour once a day like we did but like your DH he has replaced one vice for another.
I have no answers for you but want to emphasise. The only place my DH doesn't vape is my bedroom - I have banned him from vaping in there!