I know, in a FWB relationship, the focus is on sex and the two people involved aren't dating each other, but do most FWBs do the simple things that... Show More
Most Helpful Girl
FWB is a recipe for disaster and you are touching on one of the many reasons why.
FWB is just another repackaging of the classic casual sex situation to make it sound good and entice people in to it. In my experience, using the word "friend" is a pretty iffy proposition since I can tell you my friends treat me much better than most FWB partners would.
So, to your specifics, can a FWB hold your hand? Well, since it is nothing more than an extended one night stand that is focused on sex and supposed to be void of emotion, hand holding is not sexual. It is not an act of sex, it has nothing to do with sex, so in my experience it would not be a part of this. Touching hands during sex, sure. Anything during sex other than saying "I love you" can be a part of sex.
FWB can and do kiss, they can also cuddle after sex, but those acts are or can be a part of sex. If you actually went out with a FWB (which you may or may not do) and you were drunk, I would totally see that he could put his arm out to you to hold on to but part of that is just extending a general common courtesy to someone.
Anyways, there really are not rules, you supposedly can work some of this stuff out by talking about it, but in reality I would say Jerseye410 is right on. One or the other person involved ends up with feelings and more times than not, those feelings are not reciprocated. All relationships evolve or devolve, including FWB (which I hate to call a relationship). So, with FWB they usually eventually just stop hooking up or one person ends up feeling hurt.