Speaker position looks pretty good. The thing that jumps out to me is the dormer window cubby space. Ideally the room should be symmetrical behind the speakers. The reflected back wave sound will be different for each speaker and that will effect imaging I would think. But most rooms have their design issues I know mine does. However open baffle are the best choice for problem rooms as they tend to interact the least with the room.
Just do lots of experimenting with positioning including the seating position. Is it away from the back wall? That helps as well with reflected energy bouncing off the wall next to your ears. I find that when setting up speakers for the first time in a room that it is easier to leave the feet or spikes off so you can move them around easier. Once you find the best position then put them back on.
As for cleaning I just use a Swiffer duster.
It may help break in the NX Otica woofers faster without the subs but I wouldn't worry about that. Do play with the crossover settings once they have broken in for a couple hundred hours but in the mean time just sit back and enjoy the fruits of your labor.