Spares??
Good question. I played my stereo while playing catch football/frezbee and ran down the battery. Didn't break but required a back-up "jump battery" to restart the Jeep.
Otherwise NOTHING has broken. I try NOT to break though. I'm not into bending or breaking things just to prove my trail cred, as I used to be. That habit as gotten way expensive.
Drive it like to you want to keep it!
Best of luck, but go prepared.