Hi. Can these be worn walking around paved streets, shopping, etc.? Thanks

Put them on and prepare to be amazed. My last flip' was made by NIKE and I would only use them to walk less than 400-500ft. If I had to walk 3 miles in a flip this would be the one I'd use; & there is no second place choice. ENJOY!

Will 9d(m) us fit a 8 and half?

That would be a safe bet. Reef Fanning are extremely accurate in their sizing and seeing is how there are no half sizes, I would definitely go up instead of down ... no one likes their toes coming out the front ; )

Will it be ok for tropical rainy season? Does it take long to get it dry again? Any persistant smell?

They should be fine in the rainy season. I use mine for washing cars and other things outside. They do not seem to absorb much water so they dry quick and do not smell. Their slip resistance is almost like deck shoes.