Why do some theists flood and inhabit the R&S section with questions about atheism or rant about atheists or science? ?

Many of the people posting here are trolls who do not necessarily take the views they claim to take (often the opposite) - and instead are simply posting to get reactions.

By continuing to react to them, you guarantee their continued presence.

Freedom of the press or Answers Everyone has a right to ask whatever they want to. Maybe that is upper most on their mind. Who knows.

If you look you will find that R&S is a subsection of Society and Culture.

So religious questions are going to be seen by none religious people.

If you don't like our contribution why not get together and tell YA to make R&S an independent category.

Then we would never have to come across each other.

Could be a number of reasons.

For some, its a way to assert themselves when they don't feel they have any power in their real lives. Could be they live in their parents basement and don't have any control over how they live.

For some, its how they were taught to "fight" against people that don't believe as they do. Its relatively harmless, no one actually gets hurt.

For others, they are sad immature people and they don't know any better way to express themselves.

Because they cannot defend their ridiculous bible, Christians try to take the monkey off their back by trying to shift all discussions to what atheists think. But it doesn't work. It is funny though. 

It must be the insecurity, fear, resentment, immaturity, and trolling 

If one reads here only a few days, it becomes pretty apparent that they are NOT trying to convince us, but themselves.  They know we won't be convinced by rhetoric, but they sell it to themselves.  The fact that we do not fear their pretend ogre frightens them further.

It’s a sign of the end times. 

R&S has the most psychotic user base. This section makes Politics look like baby’s playing in mud. 

Because their beliefs are so weak that they have to constantly try to validate them.