Okay, a few questions

The first MIGHT work with Leo/Banon. Well, probably work, until they are replaced by different character stats using that actor (the two guest slots) up until then it should save their name with their stats. Haven't tried it though so they very well might have left it out of the save data for some strange reason.

The second, the thing with Swdtech if I remember correctly is normally only Cyan learns/unlocks the "spells". As for replacing shock/runic using a relic, without some expanded list and a little bit of extra code you'd need to replace one of the items that already swaps a command (such as dragoon boots or the fake mustach or the others.) Of course if expanding that list is as easy as adding new entries to the list of commands that need their spells calculated... its just a matter of changing one byte that says how long a list it has to check then relocating that list of commands that can be replaced to a location that allows it to hold another value. (Well actually should be two list at least, one of commands that can be changed and another of commands they change to). At that point you could just unlock all Swdtechs and run with it without further editing (should work similar to Gogo equipping Swdtech as a command).

I say might and should alot because I'm a bit rusty and tired atm, forgive me, but I'm fairly certain on all accounts.