I think you're WAY over-thinking this. Your Parents love you, and are proud of your appreciation and talent for music. The didn't buy a beautiful bass for you to lay a guilt-trip on you. They're probably secretly sad and confused that they spent hard-earned money on an instrument to commemorate your talents and graduation achievements, and for some reason they can't fathom, you act like you don't appreciate it. Do them a favor, make them proud parents, and play it, and enjoy playing it.
Don't worry about the inevitable dings and scrapes that will come with playing it. My bass has about $4500 invested in it, and its been dinged, fallen off its stand, been fallen into by drunken dancers, etc. And in spite of all that, I would still have to point the marks out to you. As someone said earlier - woods are hard, so don't worry about it, it will survive. And I love playing my bass, and enjoy the compliments from people who appreciate the craftsmanship and sound of it. The bottom line is, it is not a display piece, it's been built to be played.
How much richer is classical music because violinists aren't afraid to play their multi-million dollar Stradivarius violins?
As with all possessions, they can be stolen anywhere, anytime, including from your parents house if a burglar breaks in and sees it. I've got to wonder, if you worry this much about your bass, how do you handle the rest of your life - germ infested restrooms, tainted food, politics? You're too young to be this obsessive about your life. Material possessions will come and go over the years of your life, some sold or given away by you, some forgotten and lost by you, and some taken from you. For however long you have your items/favorite possessions, enjoy them while you have them, and treasure the memories you will make with them.
Now go grab that bass, make your parents proud they bought it for you, and make memories with it that you will treasure for years to come!