First one a good guess. For second I'd also bet on one towards the end of the soi on left side too going to the park. Mostly of Africans bring customers there.
If it is not yet clear, since a couple of years the Police is targeting in and around the airport in Phuket to catch the folks with expired visa BEFORE they pass check in and go to the immigration and pay the fine.
yes, this is normal for them in Rome or Milan, urinating or worst in fountains or on pavements during the day and in plain sight - We need more Trump in the World
On BTS, yes there is. Senior Thai get discount, not senior foreigners (even if living and working in TH, as one needs a Thai ID card to apply)
On MRT I recently topped my Senior card and got the Senior fare.