I'll share my conclusions and guesses. I read the first 3 pages of the topic, forgive me if I've missed somthing.
---What I think is for sure...
-Each time a Special move is cast, the tome on Robin's hand changes and will remain in his/her hand until a new Special move is used or the tome is depleted.
-Jab changes depending of the tome Robin is holding. It can be seen against CFalcon and Kirby. With Falcon, Robin uses Elfire tome to do a
3 jab combo. But with Kirby he uses (after the second jab that can be seen clearly
here) a jab combo with a jab finisher at the end.
-Neutral B is a chargeable lightning tome that "evolves" the more you charge it and can be stored like Samus's Charge shot of WFT's Sun Salutation. You can see Female Robin cast Arcfire then a stored Arcthunder at the trailer.
-Arcfire is side B. It traps like Ness' PK Fire and got a downward angle... Could be very good to edgeguard.
-Elwind is Up B. Cannot be DAir because it could be easily spammed to stall off stage (at first I thought that Robin got height because he landed Elwind on Little Mac, but watching it at slowmo seems like he is send upwards before Elwind hits Mac, so yeah must be Up B).
-Nosferatu is Down B, looks like a grab or a move you can keep doing if you hold the button. Maybe you can DI out of it like Charizard's Flamethrower.
-Robin should be able to recover his/her tomes. 2 options I can think off: After you get KOed or after time.
---Things that could be...
-Maybe the tomes don't have the same durability. If Nosferatu's healing is kind of good, then it should deplete faster. Thunder and it's "evolutions" should be more durable... Assuming that charging the move will deplete the tome faster than casting uncharged Thunders.
-Tomes could be discarded. In the vid Robin discards a tome, BUT I think is more possible that he just depleted it after casting it's last Thunder (and on the vid we only got his tome disposal animation).
-As he says, he got his Levin Sword because the tome's use is limited. So I think, as has being said, that if you use a "tomeless" move you'll gain access to Levin, not only replacing the move but the Bronce Sword as well. Possibly Robin will drop Levin if he/she gets KOed.
Well, thats all I got by now