I'm just starting Act 2, and I heard that there are two endings. Do I need to finish a New Game+ playthrough to get the other one? Please answer without spoilers to the game and to the endings!

Is there any fast and easy way to get Mira and U-Material?

I am at 10 hours mark and beat prolog and begining of 1 chapter. It kind of feels easier then previous games. Prev games were hard at least at beginning. I mean I don't receive big damage at all (except bosses s-crafts). I just go forward and press crafts mindlessly and maybe heal sometimes. Is it ok? Will it be better later? Maybe some bug?...

I go first. I despise Rufus. I would like to say the reason but i don't want to say any spoilers.

I understand that there is auto-save in this game but where do I find the saved to open it?