who is more likely to get injured doing small tasks - Lonan
who worries more about the other - Rosette mostly because she worries about everything
who is more afraid about the other leaving them - He’s not afraid she’ll intentionally leave, but Lonan, since he’s more aware of how connections to other people can be torn away without warning
who is more likely to leave (for any reason) - Lonan. Were he presented with the opportunity to return to his original world, he would be very very tempted. So much so, he kind of hopes he never has to make that decision
who is more likely to drunkenly confess - Rosette, since she’s a super lightweight
who is more likely to push the other away (for any reason) - Lonan. He is the one getting with someone who is essentially an AU version of his dead fiance. While he doesn’t have concrete memories of the Rosette from his timeline, he has flashes of memory. Sees things in his dreams that let him slowly piece parts of his past together. When/if he makes the connection on who Rosette is to him, he has to face the reality that while this may be a version of Rosette, this still isn’t his Rosette. Staying with her is perhaps a betrayal to the women he loved and lost. He would also have to face how he’s maybe only drawn to her because she reminds him of the women he’s been subconsciously missing ever since he came to this world. Chasing a ghost.
who picks fights more often - Neither tend to pick fights, but Rosette, once she’s more comfortable around Lonan, will push him on issues more. Not let him drop topics just because he doesn’t want to deal with them.
who usually apologizes first - Both are the type of people who don’t tend to stay angry for long and apologize quickly, so it really is both. Maybe Lonan slightly more.
who is more likely to withhold their feelings for the other - Lonan, particularly given the above point about why he’s likely attracted to her
who is more likely to lash out at the other - Rosette, for the same reason as why she pushes him on topics he wants to drop.
who gets more jealous - Rosette more so than Lonan. She doesn’t like to feel jealous, so mostly just tries to push down the feelings or talk to Lynn about it.
who is more likely to support the other in a relationship with someone else “as long as they’re happy” - Both would. Lonan because he would rationalize that he’s not even from this world, so of course Rosette would have someone from her own world she was meant to be happy with. He may have lost his own chance to find happiness with a loving partner, but he shouldn’t deprive Rosette that chance just because of his own selfishness. And for Rosette in the reverse situation, not only is she a kind person, but she’s seen how much Lonan suffers from the circumstances he’s been put in. She just wants him to be able to find happiness after all that he’s been through.