The opposite of generous is selfish.
Calculating means to act in a scheming and ruthless manner. The opposite of calculating is "thoughtless".
"bean counter" is a type of person, it doesn't really have an opposite. But to be a "bean counter" means you are overly concerned with numbers and budgets and controlling the cost of things. Like if you were a farmer and you wanted to count every single bean that you put in your truck before going to market, and then every single bean you brought back, so that you would know exactly how many beans you sold. The name "bean counter" can be harmless, or people can use it as an insult.