If the place where you do wudu is inside the bathroom, then it is makruh to utter the name of Allah in this place, even though it is prescribed to say Bismillah when doing wudu. Some scholars say you can say Bismillah in your heart without uttering it.

The reason why it is recommended to seek refuge with Allah when entering the toilet is to seek protection with Him from the devils that frequent places where there are impurities and where ‘awrahs are uncovered.

It is narrated that Prophet Muhammad forbade facing towards the Qiblah or turning one’s back to it when relieving oneself. So long as you are still at the building stage, it will be more on the safe side if you build the toilets so that when relieving oneself one is not facing the Qiblah or turning one’s back to it, so as to avoid a matter concerning which the scholars differed.