House Addition and changing Structural Beams (or material)

I recently purchased a home that has an addition off the back center of the house. Addition is open to the house and a beam was added to support the load.

On one side of the room, there is ~6" section (covered in dry wall) that should be the support. On the other end of the room the section is ~36" from the existing wall. Would it be possible to change the beam and install one that allowed me to make the room, no more than the 6" on each side? The room is 15 ft across.

The room in question is main level with a basement below and a second floor above. I'm assuming that there would need to be added support in basement if the main level support point is shifted.

The current beam also comes down to the level of the soffit. (A piece that is empty, but part of the original kitchen). If changing the length of the supporting beam, could I switch to steel and reduce the opening?

I've seen these things done for a interior load bearing wall, but am not as sure about the external wall of the original house. I'm not intending on doing this myself, but would like to be informed when I have someone could out to estimate any work.