Regarding the seating policy, technically one adult is seated next to my child
child in 18F, Adult in 18G, although with the CW seats you are of course not physically beside them (to help with dinner, getting seatbelt on / off etc..) which is why the EF seats are ideal.
Im guessing if I call the EC they will either tell me that or say I can pay to change the seats.. I may give them a call to see what they say.

Interestingly, 18E shows available until I click on one of us to initiate a seat move, then it becomes greyed out (which makes sense as it is a bassinet seat). However the EFG seats in 17 and 18 are available.