Eh.... Bringing an instrument if you mentioned it could be justified if it somehow fits into your interest in a medical specialty (e.g., ENT because you're a singer or something), I suppose, but it'd mostly be helpful if you suspect they're going to ask you to play. If you're a virtuoso on your instrument, it'd be far better to play your own instrument instead of someone else's.
Sexual orientation, OTOH... being of one sexual orientation or another does not make you any more "open-minded" than the other. I have met just as many homosexuals who are quite closed-minded as I have closed-minded heterosexuals. Heterosexual practices may get the "closed-minded" stereotype because they are traditional, but there are many very closed-minded and aggressive LGBT individuals out there. In addition, flaunting your sexual orientation is a bit of a turn-off in general. Honestly, I know I don't really want to know what you are (unless I am pursuing a romantic relationship with you) and I would expect most people are of a similar opinion. Closed-minded? No. Have healthy boundaries and expect others to respect them and/or have their own as well? Absolutely. Flaunting your sexuality in an interview is an obvious red flag for future sexual harassment or, at minimum, not having the common sense necessary to avoid making others (coworkers, colleagues, pts, etc.) quite uncomfortable.
I would also argue, in response to the above poster, that if a person's choices are resulting in poor academic and professional performance and/or other psychosocial difficulties that, perhaps, the person needs to reassess his/her choices. If one's identity is hetero- or homo- sexual s/he ought to perform ideally (socially, academically, and professionally) when those needs are met. In general, others are not going to shun a hetero- or homo- sexual individual for being different unless that person has given them reason to do so. That is, unless that individual is actively flirting with or pursuing individuals within that social group who do not appreciate said advances, it is unlikely that the "different" individual would be targeted by the group. If this postulate is true, then it is most likely that any difficulties an individual experiences due to his/her sexual orientation are due to his/her explicit behavior and not to a sexual orientation. If it is a behavioral issue, it should be changeable. (I do not wish to say "correctable" as this implies fault in said behavior and it is quite possible said behavior may be simply inappropriate for the given circumstances.) If an individual is unwilling to change a problem behavior to ensure personal and academic success as a premed student, why should an adcom believe that the individual will be willing to change a problem behavior in medical school if and when it becomes an issue (e.g., during the clinical years).