grammar - Meaning of adjective + にする

When you say

部屋をきれいにします

You mean "Clean the room" (make it so that the room becomes clean).

On the other hand, when you say

静かにする

You mean "Be quiet".

If these meanings are right, would the sentences

すべてが静かにする

すべてを静かにする

mean, respectively, "Everything is quiet" and "Make everything quiet" ?

Lastly, what would be the difference in meaning between the following:

すべてが静かにする

すべてが静かにある

Answer

部屋をきれいにします
"Clean the room" (make it so that the room becomes clean).

静かにする
"Be quiet".

The する in きれいにする means "to make", and the する in 静かにする means "to behave".

すべてが静かにする

する as "to behave~~" is (usually) used for animate things. So you can say 全員が静かにする, みんなが静かにする "Everyone stays quiet", すべての生徒が静かにする "All the students stay quiet" etc., but すべてが静かにする sounds a bit unnatural. For "Everything is quiet", you'd say すべてが静かである*, すべてが静かだ, etc.

すべてを静かにする

means "make everything quiet". ～を静かにさせる sounds more natural to me but it'd probably depend on the context.

すべてが静かにある

静かにある is grammatically incorrect. You'd say 静かである* or 静かだ.

So, for example for "All the students are quiet," you could say:

すべての生徒が静かにしている。
すべての生徒が静かである / 静かだ。

The former is like "All the students are being/staying quiet now", and the latter "All the students are quiet (now, or always)".

_{*である sounds more literary/formal than だ.}