well if you cant get a gun for what ever reason there are two things you should do for defense then at least against the neighbor types you speak of there is http://www.tbotech.com/pepperfoam.htm it is my choice in pepper spray once it hits you cant wipe it off it just re foams like shaving cream, second is there are places that teach Krav Maga, you need to find one that has you fight the other students, no other way to train for real fight than being hit and be hit back. Always try to find the best student to spar with…. less likely you will get hurt they have better control and you learn more for fighting better opponent. Make sure you fight bigger faster stronger people male and female . losses now mean nothing other than you learn in real life one chance make sure you have it right.
I dont suggest going to asian martial arts for weapon training/fighting for the unschooled too many look good but useless teachers teaching sport not combat. If you want to know what works in real life only learn the banned things from tournaments, they are ones that maim cripple and injure. i dont play for sport, but to win.
the thorny plant thing sort of works if you are going with that motif and want to do the food thing black berry briar or raspberry are nasty thorns as well but have food value,
with shooting, range time is golden but many forget shooting at a non moving paper target is not at all what will happen. Find another venue to practice combat type shooting ranges wont allow it in most cases.