Hmmm, best way to check I think is measure your existing vanities where you currently live, and decide whether you would be comfortable bending to where 880. My family is rather tall and we specially had all our our benchtops at 920. May I ask if your kitchen benchtop, where sink is to be, is also going to be low? While you may be able to live with your vanities being lower, I think having to work at that kitchen height would prove a pain.

The depends on the look you want to achieve. If you want an ultra modern look, then installing from the ceiling is the best way to go. If you want a more classic or traditional look then install the rod just below the cornice allowing enough room for the brackets/rod etc. 50mm below is good. That way you can opt for a decorative rod. I prefer s-fold from the ceiling than on a rod but it all looks great in the end either way. All the best with it. Here is some photos of some drapes we did with under cornice and on the ceiling.

I would recommend a standard seat height and if your husband is building the structure verify the thickness of your mattress. A higher bed looks maybe more luxurious but I think you are going to find it annoying to not touch the floor when you sit on it. The perfect height is the measurements from the floor to behind your knees or a bit higher. Hope it helps :)

kelly velvet stools what is the floor to seat height pls