Each time I’ve flown with EVA, it has been in Royal Laurel class so can’t comment on your additional questions. My comments were based on regular economy service on most airlines and having looked at the seat map from seat guru.

Unless you get an exit row, they will never be enough room to move out of your seat without disturbing your follow passengers (unless you get lucky and get an empty seat next to you). If you like to get out of your seat often, it’s best to book an aisle seat. If you want to sleep and not be disturbed, book a window.