I'm a lot more comfortable with the idea that the physical aspects of aikido are applicable in non-martial situations (fall prevention/survival, general fitness, more efficient movement) than I am with the explicit application of aikido to interpersonal relationships. In part because I see so many dysfunctional relationships within the art, in part because many people talking about interpersonal applications do not seem to have much actual aikido experience.
It's much easier to apply the the principles to physical activities than to inter-personal relationships, I think, because the physical are relatively cut and dried. It's clear what all the parameters are. Human relationships on the other hand have so many more parameters, many hidden, that clear application of principles can be difficult.
On the other hand, application to ourselves shouldn't be a problem. Learning to stand and move well, how we hold ourselves during verbal interactions, how we choose to express reactions with our bodies, these we can figure out. It's when we have to direct our actions outward that things get dicey.