The rack wont affect bass freqs, so just keep it lower than the midrange and tweeter to preserve clean reflections of upper freqs.
Traditionally, a glass window (especially with blinds) is said to be the least desireable surface for reflections.
The varying depth of sheetrock and window and angled shade slats is more destructive to imaging than the rack imo. The front wall reflections are critical to good imaging and the different depths and angles scramble the arrival time of reflections. Short of fully diffused front wall, a plain bare flat sheetrock is the best for imaging.
I recommend building a faux wall in front of the window. Full width, and up to ceiling if possible. If not possible to go up to ceiling then put a shelf at the top of the wall, etc. If faux wall not possible then put 3/4" plywood panel over window with insulation filling in the window gap. Paint panel same as wall color etc. Or remove blinds and make a plywood filler panel to fit Into window hole with thickness to match wall surface.
Then get rid of everything blocking reflections from the front wall area. Especially the other soeakers with moveable diaphragm. Change the side absorber panels from thick huge absorbers to smaller thinner spot diffusion panels if you think you still need them after front wall is cleaned up.
Then position the speakers correctly so that all front wall reflections arrive at you simultaneously L/R.
As for system changes and WAF, break the bad news gently, that you are an audiophile. It is a genetic affliction and this will continue for the forseeable future and only get worse. So she should enjoy these easy years now while she has them. But then you have to follow through with the threat, lest she suspect you are normal after all.
