Can we question about topic in Quran? I mean publicly scholars would say Islam is all about questions bt when we ask they say accept what is written

For eg Beating of wives is not acceptable..but when i question it they would give me answers unacceptable. Similarly women not allowed to marry non muslim men when we question it they say accept what it is written Lastly, of marrying slave women there are no slavery system now so was that verse for that period.who decides that? If that verse was for that period why can other verses be not for a period?