1. Unless you need the extra legroom of 18, I would go with any of the EMSpace seats in the front. I would avoid 19D as the legroom is restricted.
2. Yes
3. In 19 you can stow bags under 18. I'm unsure about row 18.
4. No problem in row 19. I'm unsuare about row 18
5. Definitely row 19. The 2-seat side isn't just two seats. There's a flight attendant seat in place of the missing seat.