The header for that opening is up in the wall where you can’t see it. A post inside the wall that you want to remove will have a post that supports one end of it. To be able to take the whole wall down would require a beam
from the outside wall of the house there all the way over to the inside wall that you want to keep. That is 100% the only real choice here, if you must remove the wall.
If you want posts, one will be exactly where the one exists inside the wall, right where the wall begins. And another would be right at the wall edge. Off center to the opening as a whole. NOT where you have placed them in your diagram. Not a good look, even if you balanced it with another faux post at the left end. It would all be off center.
Really, you’d not be gaining very much at all for the large expense. And you’d have lots of added expense that you may not have thought about with having to replace flooring, move electrical and HVAC, and hoping there are no plumbing stacks there.
Q
It’s thorough!
Q