uuuh... so seeing as he already got permission, why does he not just lay the rail before he got the "anyone can use it" propulsion ready? Then he could personally propel the train for his own (and liz) use.
Rather, still don't get why he bothered to ask for permission in the first place, or at least in a way that involved other guilds at all and not just "personal property"/"leased by noble for personal use"? He could still make a secret subway tho.
Also, that guild renewal system seems stupid. Like it might have some use, but in a world where people can't travel quickly, and additionally overall might be required to stay in a city for years (because travel is too slow to have any vacation long enough for it), why the hell does it expire so fast? How is the system setup for students and such normally? Since I doubt this is a very rare occurrence, but noone before liz has seemingly had it become an issue.
Also, why can't she just renew it in any guild, instead of having to travel to a specific one? Like, even if she doesn't start main'ing another guild, it should really have had systems in place to let you renew it for your real main, through a proxy.
...Or you know, renew by mail.