Re: LOL Wedding night issue
You can actually ask him to leave the room for say fifteen twenty minutes while you change if it is such an issue. Most would be accomodating enough to do that.
For makeup, you can go to a washroom, there is no reason to be running back. Why are you running? There’s nothing clandestine in the need to wash your face free of makeup surely.
As for ghusl, it is a case by case situation. You can do fajr before all of this and then proceed (most weddings and post wedding functions take ages anyway) or you can ask your husband (surely if you two have “performed” you have enough comfort level to ask him what to do about ghusl and where)