Hi joeyc
Good luck and enjoy your new Pentax 14mm F2.8. Just a few words of general advice when composing interior real estate photos. I've taken the liberty of "adjusting" one of ivoire's images (his original is the bottom one) to underline the point, but I personally find it preferable to keep the plane of the sensor perfectly vertical when composing interior architectural photographs. Simply adjust the perspective of the image by either raising or lowering the height of the tripod as required, because it avoids the undesirable effect of "converging verticals", not to mention an awful lot of unnecessary work afterwards at the post-processing stage.
You might also be interested to learn about a remarkably clever piece of free software entitled
ShiftN ShiftN
designed by Marcus Hebel, which I discovered some while back. Click on the link below to discover more about it.
https://www.pentaxforums.com/forums/583358-post48.html
PTLens is also free and does a great job of removing unwanted lens pincushion/barrel distortion, vignetting, chromatic aberration and perspective:
PTLens
Best regards
Richard