Oil first, into clean skin, then the roller over the top. The oil is what lets the steel glide instead of drag.
30 seconds to a minute on each area, and 5 to 10 minutes for the whole face. Start shorter if you are new to it and keep it moving throughout.
At least 15 minutes in the freezer. Let it settle and test it on your inner wrist first. For sensitive skin, use it from the fridge instead.
Yes. The oil is a daily product, and the roller is fine daily once your skin is used to the cold. Build up rather than starting at the deep end.
Solid metal over a freezable core stays genuinely cold through a full pass. Gel sealed in hollow plastic warms up partway through. Metal is also non-porous, so it cleans completely.
Cool water and mild soap after every use, then pat it dry. Never put it back in the freezer wet, since surface ice can cause cold burns.