What hasn't been "unlocked" by Revelation book?

Revelation book is the last Holy Scriptures' book. Some brilliant or awesome events and characters in this Book aren't [even within a same branch of christianity] understood in unanimity as to what they actually stand for. Is it possible to know which parts of this precious Book are still totally "covered" for human understanding near 2000 years after it was written by The Revelator? Is there a part of this Book that is still kept "locked" by God for understanding really? Which part is it? Why Christianity world stick to the "Gospel" books in the Bible and ignore "Prophetic" books also in there? What is the most important Revelation Book prophesy for the present world generation? Which authority is that which tells me to trust such prophesy? What are the dangers of going about our lives without due care to God's prophesies? If humans are saved by Jesus' grace why care about events and characters all written in an amazing folcloric language as in Revelation?