

There are different ones for different kinds of writing (general, academic, journalism, and more). Chicago Manual of Style is one of the general ones. It’s good, and considered authoritative, but you have to buy a copy or an online subscription.
A free one that I like is Purdue OWL (Online Writing Lab from a university). It’s easy to understand and has good info.
That might vary by person, but for me it’s not. If I had to pick between being able to see and being able to hear, it’d be hearing, hands down. Being able to see is amazing and I’d miss it, but hearing is just a whole other dimension.
Being able to know how someone is feeling, just by hearing their voice. Listening to music and hearing all the shapes, colors, and feelings that come with it. The colors aren’t always ones you can see, like blue or yellow. It’s hard to describe. I’ll close my eyes and just listen at a concert (not the whole time) and same with TV, a lot of times. I usually remember it better that way.
If I have to find something in a backpack, I’ll often do it by feel. I probably look like a raccoon washing its food, but it just works for me. You can tell things apart by feel and sound.