I think you can attack unescorted transports, because they would not have any larger combat ships to hide behind. This would be the only occurrence though because the kamikaze pilots are trained to go for the big combat vessels and not the weak, cheap transport vessels.
No, you can’t. The errata has not overridden the pac40 rulebook, and the errata applies to Alpha 2. Alpha 2 only changed the triggers to kamis but it didn’t change how they work.
Kamis can only target surface warships, and it’s not an attack (so deceptive to call it that). it’s ONLY a defensive action declared at the end of a combat move (not during a combat move) in exactly the same way scrambling is declared.
This also has never changed, it’s ALWAYS been if combat move ENDS in a kami symbol SZ, which ALWAYS means either combat in the seazone or an amphibious assault. You can’t combat move if you aren’t going to conduct combat.