Watching the house literally around you in the pursuit of sonic perfection and reconfiguring the structure for no audible gain in this situation is not a good idea, IMO.
The slim column is a simple pipe column and the beam is most likely a few joists nailed together to make the beam. I would suggest just painting the column to make it visually disappear. I agree with the acoustician, that its impacts sonically are negligible if not zero.
You would be better served treating the ceiling and using the Room Eq Wizard to dial in your listening position. I have an odd-shaped room with no hopes of doing real acoustical treatments. So I used Audyssey to "tune" as well as I could to the space that I have. It helped. But for late-night listening, I'm on headphones with my eyes closed and a short bourbon in one hand.