Some more nuanced questions...

I want to thank everyone over here for a lot of the comments I've been able to read to help me out in narrowing down things. I've been a long time reader over at r/Kindle, And I've been impressed with the Scribe since it first came out, But wanted to wait a bit before just getting one.

Amazon has a pretty good deal with a refurbished first generation one with premium pen, that after my trade-in of my old Kindle Keyboard, I'll be able to walk away for less than $300 with a case for a 16 gig one.

The sub already answered my question about landscape mode with two columns as well as my size that I would need. But I have a few more nuanced questions about some of the experiential stuff that I wasn't able to find when I was looking...

1) regarding landscape mode, is that something that I need to set for each book individually as I open them? Or if I set that as my preferential reading habits kind of like how I set my font size on my current Paperwhite 7th generation, that it will always load two columns landscape 2) Is a screen protector necessary? I haven't worried before on my Paperwhite/Keyboard/Fire that I have, but this is built more for writing too, so more interaction on the screen 3) I believe the nubs are also replaceable on the pen, is that necessary too?

Thanks in advance! I'm planning on pulling the trigger within a week or so, so I haven't even initiated my trade-in on my current Keyboard model yet.