Hi, I started played Rorona a few days ago and I'm liking it a lot, but there's a few things that I'm unclear on. They're as follows:

1. How is damage calculated? Is it just Atk - Defense? Or is there more to it?

1a. Crits deal 1.5x I heard, but I dealt 40 damage on a crit when I normally would do 25-28. Do crits do anything like ignore defense Stat? Or is it just 1.5x and I got weird rolls?

1. Is there any chart or reference for stuff like how much damage items do, or how much health/mp items heal?

2. Do the different endings actually do anything? I know there's a post-game, do they affect that? Or can I just play the game without worrying about making decisions for the ending that would be most beneficial.

3. Are Front/Friend Requests random? Or do the same ones show up on the same days every time?

.

I plan on playing the other Arland games as well as L&S and the newest one, the ones available for the Switch. I assume the Arland ones are fairly similar on their mechanics, but is there anything in the other games that I should be aware of that isn't explained by the game? (I guess that's question 5)

Thanks for any help.