Yes
There are absolutely NO 'side effects' or negative effects from taking a shower during the menstrual cycle (or a period).
Get out of the shower and go in the bathroom
Yes. It can be a little messy, but sex in the shower solves that problem.
Yes, but it will be messy. You will need to take sanitary measures, such as doing so in the shower.
No, taking a shower on your period isn't bad at all - you can do anything during your period that you would do any other time of your menstrual cycle, and just like any other time of your cycle you should bathe regularly to stay hygienic.
A brief period of rain is actually called a shower though I don't have a clue why it is called a shower, you don't wash yourself in it do you.
It doesn't, when you step into the shower, all the blood is washed from the outside of your vagina but not the inside. You still have your period.
It doesn't, when you step into the shower, all the blood is washed from the outside of your vagina but not the inside. You still have your period.
You use it during the shower.
Yes.
You do - there is nothing about being in the water that stops menstruation, but what little blood that does leave your body during that short period of time would be diluted by the water.