if am a teetotaller and some one laced my drink with vodka or any alcohol without a smell, would I know?!

All alcohol has a smell and distinct taste. Vodka being odorless is a myth, take a shot and then ask a friend if they can smell it. The answer will always be yes. To answer your question, yes. You would definitely notice a difference in the taste of your drink if alcohol had been added without your knowledge. Word to the wise, never leave your drink unattended and if possible drink out of bottles that you can cap and take with you. If you ever suspect something is wrong, abandon that drink and order another one.

It depends on your sensitivity to the substance. Also masking factors (flavors, sweetness, amount of alcohol, how "developed" the alcohol is.. ect.

For me, I likely would because I'm fairly sensitive to alcohol (can easily detect even if less than 0.5%) and generally dislike the taste; but not everyone is this sensitive. Vodka is pretty distinct though in flavor and taste,so it would very noticable for me.

I think you would know but the advice about not leaving your drink unattended is good advice.

Your drink would taste different to usual.

You will taste something odd, and alcohol does have a smell of some sort, you will know.

You likely wouldn't know. Don't leave your drinks down and walk away. Safest bet.

you would start a craving for a doner kebab