[Scott]

You don't withdraw books from the library, you conduct research at the library.  Books you rest-to-read are discovered in game and carried in your inventory, bought, sold, etc.  That answers most of your questions right there (I hope)!

Other questions: 
Resting and resting/reading can be interrupted.  Having a place to rest doesn't guarantee safety.

You will tell me that I can't sit around in a dangerous place and read  a book...

I will?  I doubt it, but point it out to me if I do.    Seriously though, I get your reasoning, but the stuff you'll be reading isn't the day's paper or a comic book.  Since you're (typically) not just picking up some random tidbits of info, but learning or expanding upon real-life skills, I like to bundle it with rest.  Like everything else, it's a compromise between game rules and realism, but I think it's a sensible compromise.  Imagine trying to read an engineering textbook while standing on a busy subway platform.

[Ellorien]

You don't withdraw books from the library, you conduct research at the library.

Gosh, you burst my bubble, man. And here I was imagining how I would be returning the half-burnt, dripping with blood and slime books to the stunned bespectacled librarian. 

That answers most of your questions right there

Yes, thank you, good sir. 

I will?  I doubt it, but point it out to me if I do.

So, a point to you? 

Imagine trying to read an engineering textbook while standing on a busy subway platform.

I can easily imagine this because I used to read thick textbooks standing on a busy subway platform a lot.

[Oscar]

I can easily imagine this because I used to read thick textbooks standing on a busy subway platform a lot.

Yep, I can too. I had to make good use of those two hours I travelled from Uni to home.

[Villfarelse]

I can easily imagine this because I used to read thick textbooks standing on a busy subway platform a lot.

Well, then try to imagine it with these guys breathing down your neck

[Ellorien]

I can easily imagine this because I used to read thick textbooks standing on a busy subway platform a lot.

Well, then try to imagine it with these guys breathing down your neck

No problem. That's just a typical late-afternoon subway beggar. 

Try this one.

[Gregorus Prime]

I think the real issue here is that you can't possibly sit down to read ancient tomes of blasphemous magick and forbidden truths that would drive us pathetic humans to insanity from sheer horror unless you have on a fez and smoking jacket, with some Vivaldi playing on your gramophone while your Negroe manservant serves you cucumber sandwiches and fine brandy and a roaring fire warms you.

I guess you can, if you're some sort of low-born small-minded goon. But damn it, we're gentlemen.

[Scott]

It is difficult to imagine someone perusing the Necronomicon while eating a sandwich on a bus, jammed between two fat factory workers.

[Oscar]

It is difficult to imagine someone perusing the Necronomicon while eating a sandwich on a bus, jammed between two fat factory workers old whores.

True story

[FireStomp]

It is difficult to imagine someone perusing the Necronomicon while eating a sandwich on a bus, jammed between two fat factory workers.

Well, maybe it's an issue for snobby types like you, but it worked fine for me. Granted, only one of the workers was fat. Maybe that did it.