What force should the vertical members next to wall openings (chords) be designed for in perforated shear walls? Is it the same as the end chords?

For the perforated shear wall method, the internal vertical members are not designed to resist tension due to overturning but for compression due to overturning the design force would be the same as would result from using a segmented shear wall method. See Special Design Provisions for Wind and Seismic and the Wood Frame Construction Manual

 Read the Perforated Shear Wall Design PDF for more information.