#1 purchase for bike owners traveling near cars: Garmin Varia. Cheaper ones exist, but this one a) pulses at drivers to let them know you exist and b) informs you on your head unit that car(s) exist(s). It's not a panacea but it'll turn a bad situation (inattentive driver) into a better one.

I feel like a paintball gun on a shoulder strap might help to discourage that behavior from motorists

I've been riding my ebike in public, aggressively, for over 1000 miles.

Where are you located, and what behavior of yours do you suspect these people are taking such issue that they're threatening you with their vehicles? Just being a cyclist?