Although TAP doesn't publish a legend for their seat maps, I'm happy to take a stab at the two questions you posed above based on my personal experience as a TAP Executive customer.
Originally Posted by
blue bear
3. What is "WC row" in the above seat selection map? Water closet?
The single forward lavatory on the left-hand side (there is a galley there too, on the right, but it's not reflected on the map); yes, water closet.