Instead of a spray bottle, how about something that makes a loud noise? Like, a metal coffee can with nails in it. When the cat misbehaves, give the tin a good loud shake. It may startle him more than the spray bottle, and if he associates it with certain behaviors maybe he’ll stop those behaviors. I say maybe because he is a cat, and cats are not like dogs. When he does something you like, such as sit calmly on your lap or let you pet him without attacking your hand, give him a small treat. Set aside some time each day, preferably at a time when he seems calmer, to work with him in this way. Keep the treats and noisemaker handy, and use them consistently. Don’t let him get away with something inappropriate because it’s funny or cute.
You say ignoring him when he attacks you doesn’t work, but would it be possible for you to ignore him by shutting him out of the room? Or, you go into another room and close the door.
He might need toys and games that require a bit more mental power than your average chew toy. Or, toys that give him a lot more exercise. Do you have a laser pointer so he can chase the light around? How about one of those cat toys that looks like a fishing pole but has a feathery toy at the end? Or something like this ball chase toy?
If you really want to give his brain a workout, which is a good outlet for his energies and may help curb his unwanted behavior, you can take advantage of how smart he seems and try to train him to do tricks. Besides stimulating him and giving him something to do besides attack you, it could be a good bonding experience for both of you.
Finally, you could try some calming products for cats. I haven’t tried these and have no idea if they would work, but they are pheromone based and claim to calm cats to prevent certain behaviors. It might be worth looking into. This website I keep linking to is my favorite pet supply site. They just have the coolest stuff and great customer service. However, a lot of these things you can find at any pet store.
If he hasn’t been neutered yet, please make an appointment with the vet to have that done as soon as possible. Besides being better for his health and a small thing you can do to help control the cat population, it may also curb some of his aggressive behaviors.