DISCLAIMER: everything below is my opinion.
I personally love MC and Nami's "weird relationship". You can tell they are something different from regular siblings, but not precisely lovers.
And the fact that it was acknowledge in such a natural way was fantastic. Too many times we see stupid cliches "ohh I saw my brother cock, yesterday i felt nothing, now i wanna be her cumslut". Obviously, I was not expecting that kind of crap in SG or any other of Ocean's games, but still the way it was acknowledged felt wonderful. The amount of emotion from Nami from hearing MC's kiss a girl is amazing.
They have always been weird. But now they are at age and MC going out of his shell is moving things in Nami too. As MC could not help but react to Bella (for better or worse), Nami cannot help but react to whatever is happening.
She is truly a fantastic character and I would be totally into her if not for Bella. Like, you know I tend to whore around in pretty much every game. But here, I am acting nice to everyone, but romantically I can only see Bella.
So about the tits, I chose the last option, of course. Sorry Nami, I cannot help what I like.
I have really selected all choices I am happy with, but one: the feet part. I was simply being nice to Nami, but I don't have a feet kink. I don't dislike, but never got around by feet at all and hard for me to see them as something sensual.
So I might change my answer there. That's it.