Would a human body float in the dense atmosphere of Venus? To survive high in the atmosphere of Venus, all you would nead to wear is suit that protects you from the sulfuric acid vapors in the air and a supply of breathable air. Assuming (for simplicity) that this gear has the same density as the human body (the air supply would probably much heavier), could you float on top of denser gas layers below you?

I believe the density of the gas would only have to be about as high as the density of water on the surface of the sea. And would that mean that when you pour out a bottle of water, the water would float in the air (given the temperature/pressure ratio is below the boiling point)?
No. According to the Nasa Venus fact sheet the density of the atmosphere at the surface is ~65 kg/m^3.

For comparison, water is 1000 kg/m^3. We only just float in water. 

So if you were there, in a suit that could somehow withstand the heat (464 C), the "air" would feel thick.

Maybe a person could strap on some wings and fly ...