Maria; beautiful setup, congrats. you are starting at a pretty good place.
do you continue to have the 'rattle'? i read thru the thread and no mention of a solution.
if the space issues require the speakers to set on the credenza; you need to somehow 'de-couple' the speakers from the top of the credenza to attain the refinement that the gear is capable of. it appears you are using some sort of wood 'footer' to ground your speaker to the credenza. this grounding to a vibration rich piece of furniture will be counter-productive to the best sound.
i might recommend trying to find a set of 'Aurios' or 'Pro Aurios' for sale used. you would need a set of 3 for each speaker. they will allow your speakers to 'float' on top of the credenza. you will be amazed at the additional image focus, detail, and bass articulation that would yield.
in any case, thanks for sharing your system and pictures.....and enjoy the music.