No, software being free as in beer is not a necessary condition for being open-source. And if the code is not free as in beer, the pricing model can be whatever the hell you want, as long as the code is shared when the user is licensed. That can mean an expensive license for enterprise use coexisting with a free license for (say) researchers and individual devs.
No, not in the way GP wrote. You’re not allowed to have your license discriminate between users, so you’d have to sell your software to everyone, not just big companies.
No, software being free as in beer is not a necessary condition for being open-source. And if the code is not free as in beer, the pricing model can be whatever the hell you want, as long as the code is shared when the user is licensed. That can mean an expensive license for enterprise use coexisting with a free license for (say) researchers and individual devs.
No, not in the way GP wrote. You’re not allowed to have your license discriminate between users, so you’d have to sell your software to everyone, not just big companies.
Either no one pays, or everyone pays.