What do I need to verify before taking down a wall?
I have come across quite a few houses lately where they have back-to-back closets and we have generally turned these into two walk-ins vs. two traditional sliding door (shallow rectangle).

If the wall is not load bearing it is simply demoing the walls, rerunning any electric, reframing where needed, lots of drywall patching and fixing the carpet/flooring issue.

If the wall is load bearing you may need to install a metal/LVL header.  In the cases where we have one like this we were able to install a metal header above the door (so not where the dividing wall is).  Almost all municipalities require an engineer/architect sign-off on the design.  We did come across a couple where we would have had to install the header in the middle of the closets and we just simply didn't tear down that wall - it would have added a good 1500 to the project.