Trying to open up some space in my tiny 1.5 floor cape house...

I created a to-scale illustration of my house including the rafters/joists/beams in the basement/attic. The red square is a chimney.

My guess is that the wall with the chimney enclosed within it (highlighted in green) is the central load-bearing wall, as it runs perpendicular to the basement joists... and there's a wall stacked on top on the second floor. Would that be a safe assumption?

I'm going to have to hire an engineer either way, but before I do I'd like a rough idea of where my load bearing structures are. I can't afford to have a load-bearing wall removed, so when working with an engineer I'd likely want to save a bit of time and not even consider it as an option.