If you had to choose between lightweight laptop OR the visibility of a wide screen in a laptop, what would be?

I like a medium-size screen because I like a medium-size laptop. I don't want to carry a giant laptop.

I won't buy a small laptop with a small screen.

Widescreen is not an advantage for word processing and reading text. Sure, you can open two windows side by side, but doing that is cumbersome, and consequentially, since you lose vertical space, you do a ton of more scrolling. Still, most laptops are widescreen nowadays, since the LCD manufacturers basically forced it upon us.

For your case, get a 13-14" laptop, maybe a widescreen 12" at the smallest. It's a very good compromise between screen size and portability. Smaller laptops generally have less screen area and often those under 12" widescreen (or 14" standard) will have a reduced keyboard layout, which is bad for typing. Larger laptops are less portable.