A majority of vapes and e-cigs sold in the UK are illegal in their try design according to a recent survey. Things like too high capacity of the liquid, too high concentration of the liquid, etc.
Imho they're cigarettes by another delivery method. Whatever applies to cigarettes should apply to vapes, etc. No use where you can't smoke, complete ban of they ban cigarettes. No encouragement to use by medical profession even if they're slightly safer. Cigarettes and vapes are nicotine delivery devices. Addiction devices and not healthy for users or others.
One last thing, complete ban on flavoured vapes, advertising anywhere and anything but plain packaging plus all places selling them must put them into a plain, covered cupboard just like cigarettes.