I like the battery trick, but usually only if it's a trunk mounted battery. I don't think that there's alot of room to hide one that can't be quickly found. (Follow the big red cable.) (Just my opinion, don't flame me). Plus, I like my radio stations where I set them.
Yes, you can jump a starter relay, thus defeating the neutral safety switch, but hot wiring a coil won't make it fire if it is grounded.