1) You are right, But even doe if this the first flashcart, If it requires you to stay in one specific firmware and does not let you to play new roms that requires new firmware, Price should not be the same.
2)You are right, Still, playing shitty games you can discover a great game, But is not the same as playing Essentialw.
3) Well you could do the same i will do, Use 1 3ds for online, use another one for offline.
4 It ''MAY'' be. Just... Don;t be expect a lot from a First 3ds Rom Flashcard, Is better to be surprised than dissapointed.