and when you smell something you are actually taking in a tiny fraction of what you smell into your nose. If that can happen with a molecule of eg. tobacco smoke, horse manure etc, then a tiny virus in a molecule of water can of course travel significantly more than 2 metres.
This is not correct. Water is a very small molecule - just one oxygen atom with two hydrogen atoms. Viruses consist of large carbon based molecules. They may hitch a ride on a water droplet (which itself consists of millions of molecules of water), but not on a molecule. That’s like saying Jupiter could hitch a ride on a mouse.
Smells are relatively small molecules and can become airborne and travel many metres - you can smell manure a good way off (through a mask, unless it has a carbon filter) but that doesn’t mean you’re inhaling the viruses in the manure. You’re just smelling the small molecule decomposition products. Not nice, but not infectious.
Having said all that, I think you’re right, that certain activities cause aerosols on which coronavirus can hitch a ride and travel further than 2m and so we should still be very cautious.