I have a ceiling fan/light combo with 14/3 running to a box that has 14/3 running to a different box where the power is located. I'm wondering if it's possible to put the light on the 3-way switches and then a single-pole switch at the unpowered box and have that just for the fan control? The location of the other switch is by the front door that we never use so running the 14/3 to that box to bring the fan control over there too would not be worth the effort. If it is possible, which wire from the 14/3 3-way switch would I use on the single-pole switch, the black or the red?

Please note basement outer-wall, inside frame/drywall construction (not load bearing) Bottom plate is 2 x 4 pressure-treated bolted onto concrete floor. First material on wall is 2" EPS foam insulation glued onto concrete walls, with spray foam to seal/secure as required Top plate is 2 x4 fir nailed across across bottom of floor joists. Next layer out is 2 x 2" studs at 16-centers, construction-glued on top of foam and toenailed into top and bottom 2 x 4 plates Last layer out will be 1/2" drywall, no vapor barrier. Now to the Topic: Since only 2 x 2 stud is available to support outlets and switch boxes, the plan is to use shallow metal boxes with welded side support on to stud. To protect wire - 1/2" Emt will extend from top of electrical box through drilled top plate. There will be no horizontal runs through 2 x2 studs. Each vertical run will have only (1) NM 14/2 w/g for a 15-amp outlet or (1) 14/3 w/g if a 3-way lighting switch. The NM will be fed into the EMT (not sure of any need for a clamping connector here) from above, from either; junction boxes at recessed lighting, from oversized outlet/junction boxes inside interior partition walls with full-size 2 x4 vertical studs, (conventional wall construction). Outlet circuts will originate with GFCI outlets at the interior walls Does any of the above make sense? Thanks in advance,