I see you guys worrying and all, but honestly I'd like to raise two points. First is if we got the ability to just [...] in any responses, that would address a lot. Should options presented not fit the background you came up with, you can opt out.
Second, if it's a single scene where you just kind of get to see the WoL share some of their background with a friendly NPC or something, you aren't going to get to pour over every nitty gritty detail. You might get to answer stuff like "do you have a home to go to" with "yes/I miss it", "yes/but I hated it there", "no/I wish i did", "no/I didn't need one", etc. Or you could answer questions about family like what SorceressVal mentioned. I do think some of the points Val proposed would be too detailed practically speaking (ex. exact hometown name) and I don't think a movie flashback would work here, but I mean if the options are presented right you could probably even answer stuff as a remarkably lifelike mammet.
The other thing is, I don't think it's needed to force backstory at the beginning. If you have a situation where you can step aside with an NPC of your choice and just talk a little, from a story/character standpoint you have the opportunity to get closer by finally (after a ridiculous number of quests and expansions) share a little about your WoL. Could be a very sweet and moving scene depending on how it's spun, doesn't have to effect the rest of gameplay.
Maybe I'm wrong, but it seems like in these threads a lot of the reasons people have been nixing possibilities have been out of worry that something will be taken away (like resources or a totally custom backstory) or that something will be imposed that the player isn't into. I get the worry and think it's important not to mess things up like that, but I also think some of this stuff if done in a clever way would pose zero threat. Could offer other players something to feel very excited about at the same time. If you have ways to opt out, nothing's imposed, and there's basically no inconvenience to your gaming then why not allow the features for people who want it?
Btw not asking this as like "ohohoho I am so important so many hypothetical people think the same as me" or anything. I noticed that lodestone sites tend to have comparatively more people who focus on fight mechanics while some other sites have more RPers, more glamour hounds, so on and so forth. Different collections of players seem to gravitate toward different parts of the game and I've seen segments where I seriously suspect certain options would be celebrated if done appropriately. If it was RPers rejecting a thing that would appeal to people super into fight mechanics I'd ask too. Also not looking for any kind of fight here, just chatting.