Natsu's statement being more romantic is an opinion. I would easily tell my close friends and family that I wish we could be together forever, but I am sure not telling them that their body is mine unless I intend on pursuing a romantic or sexual relationship with them. Carla being a cat doesn't change the evidence that saying "we'll be together forever" isn't necessarily a romantic statement and not proof of Natsu's romantic feelings.
Naturally, this whole ship rating is a bunch of opinions, and everything i've said or will be saying here is nothing but that.
Gray said "maybe" her body should be his, which means he's still mulling it over, like he has been doing for the entire series. If you wanted you could claim that Juvia is in the same spot she was 7 years ago.
As for "being together forever" being evidence, i already told you, it isnt, like Grays answer isnt, but saying we'll be together forever has more meaning when said between a man and a woman. Also, as Arjuna mentioned, Natsu has shown sexual interest in Lucy, groping her intentionally and showing a desire to see her naked. Intentionally grabbing a chicks boobs>saying maybe your body should be mine.
Unless we see them as a married couple, them getting married in the future is head-canon. Just because Lucy has feelings for Natsu doesn't mean that she wants to be in a relationship with him and Marriage has never been a goal for Natsu. Lucy may never grow some balls and Natsu may never be ready for a romantic relationship (the dude went 550 chapters and barely matured). Saying he's 'like Goku' is not a good argument because these are still different series with different authors. Lucy may have one sided feelings but if they never express the desire to progress their relationship than it is far from confirmed that their relationship will ever change from what it is now. I don't think this makes it a bad pairing; I am just saying it isn't confirmed to lead to a romantic relationship.
This rate isn't really the right place to debate this though since its a ranking to determine the relationships that people like the most, and not a rate to determine which pairings are most canon.
You're right, it is head canon, like this whole ship rating.
Sure, Lucy
may not want a relationship, and she
may never have the balls to confess, just like Gray
may never actually commit to Juvia and Juvia
may have been making the whole love thing up as a joke on Gray for when she can finally tell him to go screw himself. The manga's over, no one is married(apart from Bisca and Alzac) all we can do now say what we think
may happen later
Aren't you describing GruVia here? If one side is enough then Juvia having feelings for Gray for the entirety of the manga makes it more canon than any of the other major ships. Especially since she's the first girl to have feelings for her man since the beginning:
I would be, if that pansy didnt always turn the poor girl down. But yeah, ive considered Gruvia canon since the ToH arc. After watching ToH it was obvious that there was absolutely no chance that those two wouldnt end up together, it was only a matter of time.