Actually being a scaredy cat is a good amout of protection against harm,
my cats are paranoid skitziods according to my nephew, who they hide from, but I think they are smart enough to weigh the risk of strangers,
they are scared of any loud noise outside too, but they do have better hearing so things probally sound louder.
She's safer in the house anyhow, I keep mine inside most all the time except for a few minutes on a leash in the summer.
My oldest cat sounds like yours, she will play, but only on her terms, and it isn't so easy to figure out what her terms are.
feather toys and tennis balls and socks are what mostly get her going, no catnip, she only tries to pee on it nowadays, senile gal.
I also have a regular fishing pole converted to just a small toy on the end of the line and that'll really get them going,
but the older cat doesn't like it if I don't stand still. Good luck and welcome to the forum.