You should always have the latest version because it is the most stable version. In this case 8.5 had bugs that broke the game so I worked as fast as possible to release the current version (8.6).
Small investments that make the game visually better. It can only get better!
It is precisely the saving that is done to avoid what you are doing. It is also to prevent you from saving just before a decision. It's all a lot of nonsense but it's for people who want everything to be "permanent", you know.
And no, there's nothing you can't see in normal mode. All the hard stuff is visible in normal mode but it's not repeatable.
This is all going to change in the next version as I'm reworking the hard mode to add exclusive stuff to that mode. One of the important changes apart from adding an exclusive token, is to put back the save and rollback option but... if you disable it you will be rewarded (it's still to be decided what but it will be something related to materials/gold).
If you want to see the new intro you can either start over or wait for 9.0 to start a new game. At the moment all the saves will be compatible. NOTE: This will change in the next version because I'm going to clean the code when loading the game and the saves previous to 7.2 will be obsolete.