many of the Mystics I've seen wear their horns on a string 'round their head or have them sewn into a hat/bandana. it reduces their make-up requirement to elf ears, which can also be attached without glue if you're skin is really that sensitive
as for roleplay, of course it trumps everything. you can have fun and make a great game playing a slime-mold, if you're clever, have a good plot writing team, and the campaign's amicable. 'course, you'll still be in the minority, have no racial advantages, backers, or racial plot. i'm not saying you can't have fun playing a Human, just that they get no love. they don't even get a write-up in the Rule Book, they're described as the "default race" (ARB pg. 38). that's just cold
as for roleplay, of course it trumps everything. you can have fun and make a great game playing a slime-mold, if you're clever, have a good plot writing team, and the campaign's amicable. 'course, you'll still be in the minority, have no racial advantages, backers, or racial plot. i'm not saying you can't have fun playing a Human, just that they get no love. they don't even get a write-up in the Rule Book, they're described as the "default race" (ARB pg. 38). that's just cold