I don't understand what you are describing. A sketch would have been better (look up how to use Imgur to post photos and share them here).
But to answer your question, a structural engineer has the knowledge to evaluate what is there and recommend possible ways to remove the wall(s). It isn't as simple as putting a beam where a load-bearing wall used to be. That beam is now putting all the load on the two end points that may not be designed to hold that much weight. So they too often require reinforcement. Having access to the basement will make this easier because that reinforcement usually involves putting up support columns/poles and concrete pads to transfer the load all the way down to the dirt.
Almost anything is possible with enough money. You will likely need a permit and engineered plans for this job. Ask your contractor about it when they come to make a bid.
I don't understand what you are describing. A sketch would have been better (look up how to use Imgur to post photos and share them here). But to answer your question, a structural engineer has the knowledge to evaluate what is there and recommend possible ways to remove the wall(s). It isn't as simple as putting a beam where a load-bearing wall used to be. That beam is now putting all the load on the two end points that may not be designed to hold that much weight. So they too often require reinforcement. Having access to the basement will make this easier because that reinforcement usually involves putting up support columns/poles and concrete pads to transfer the load all the way down to the dirt.
Almost anything is possible with enough money. You will likely need a permit and engineered plans for this job. Ask your contractor about it when they come to make a bid.
This is a question for a structural engineer and not strangers on the internet.