Yes confirmed on all your questions. I recommend ordering the First Aid Kit so that you have extra parts (you may need some extra springs with flippers and the other parts are good to have – I have damaged springs when removing keys).
Though HHKB split right shift is not compatible with regular right shift as the barrels are in physically different positions for those two keys (all other key positions are compatible with the different language key sets).
Super, thank you. Could I ask a few clarifications? I’m planning to order an F77 with an ANSI/US layout. Is it correct that the Arabic keyset although being an ISO layout can be swapped in and out with the ANSI/US (by me the user, that is)? Also, is it still the case as mentioned in one blog update that when ordering the ANSI/US keyset all 104 keys come with it? Is this the same for alternate keysets like the Arabic one?