Focus, grasshopper. Take only what you can use profitably. You will get a sense for that with experience.
As for your current game... that sounds pretty darned bad. You may need to poprush some marketplaces and courthouses, and you will probably have to disband a chunk of your army.
When I warmonger, I still do my own research. Very little tech comes my way via bullying. It's not terribly effective.