I hear people all the time talking about how they can screw your car up and you will never know it, things like taking the rotor or putting sugar in the gas tank. Does that really mess the car up? What are some other things they could do that could possibly be avoided or protected?
to prevent your gas tank being sugared, use a locking gas cap. as for other things, all you can really do is check over your car on a regular basis to make sure people dont do things like drain your oil, or cut your filter, loosen your lugnuts, cut your brake line, etc.
Dont forget, people switching around you ignition wires, putting boogers on your windows, or putting light amounts of vaseline on the door handles.
None of these have ever happened to me, but some friends are always playing stupid jokes on each other. They dont mess with my stang cause they know what they'll get and they have respect for classics.
A good way to solve the engine problems is with locking hood pins. If you don't wanna drill holes in your hood, then you can always make a locking mechanism like on new cars.