A few things that stand out to me:
If Fleurent is a noble, his name should probably be Fleurent de Gisoreux.
It sounds improbable that - in cramped Ishgard and amongst gossiping nobles - he could keep two people a complete secret. Even more so when they're an 'exotic' foreign race that will stand out. Rumours will certainly spread.
I haven't played the dark knight quests, so that description doesn't tell me much - and I'm not really sure what you're meaning by "what Haurchefant does" either. What happened? What did he do? It feels like too much of a handwave - "this really important thing happened but I haven't worked out what it was".
Also, from what I can get out of the lorebook, it sounds like Fleurent would be facing trial by combat for [whatever it was], so you could maybe work that into his redemption. (Also have a look at the MCH Lv50-60 quests, where the guild basically got accused of trying to start a revolution, and had to undergo trial by combat against a dragon...)
And what are these particular ideals and concept of justice that he's passing on to Lana? Because that's a big part of understanding how your character is going to think and act.
(Also a nitpick from your linked post on the other site: the Ishgard expansion is titled "Heavensward", ie. 'towards the heavens', not "Heaven Sword".)
House Fortemps (no second 't' in the spelling) is most likely still employing foreigners. At least, there's no indication that Artoirel would change it.
There's also the Lv50-60 miner quests where you're working with a group of mercenaries hired by the vaguely-defined "Count Fortemps" - by the way time usually works in the game, we probably should assume that's Edmont even if you're doing the quests post-Heavensward, but nevertheless it's written so it could work regardless of who is count at the time.
House Haillenarte also seems to be open to employing foreigners, even before the end of Heavensward.
Most prominently (though not so useful for indicating the overall stance of the house) Stephanivien hired a Lominsan to work for the machinists' guild as marksmanship instructor.
Some levequest descriptions indicate that there is an Ul'dahn pugilist training knights "as part of a military arts exchange facilitated by House Haillenarte".
And they are also in charge of the Diadem, which is (more-or-less theoretically at this point) specifically recruiting adventurers post-Heavensward.
Emmanellain and Laniaitte also turn up in the start-of-Stormblood Lv60 weaver quest in Ul'dah, apparently specifically to show off the High House costumes, so presumably trying to promote foreign trade.
And the lorebook profile for the Count de Durendaire is prettymuch all about his stance on foreigners - originally sharing Edmont's "desire to open Ishgard's borders and welcome foreign influences", but he became more conservative after the loss of his son. Now with the shifting situation in Ishgard he is supporting Aymeric "in a pragmatic bid to retain influence and preserve the status quo".
House Dzemael is (as always) the mystery card because we really don't hear much about them. Tarresson (the ex-count and a major character in the Moogle crafting questline) seems like he'd be open to it, but then he seems to have little interest in returning to Ishgard. Beyond that, they tend to be the designated antagonists, and the closest we got to an opinion on foreign trade was the Lv60 botanist quest where someone from House Dzemael tried to sabotage the Haillenarte botanist growing foreign crops at Camp Cloudtop... more likely due to petty politics between the houses, but that's all there is to go on. I don't think we've heard anything of them since the end of Heavensward.