Are since there are multiple people Use is for one person For example Is Mrs Li in a big shop? Are Mrs Li and Kitty in a big shop?

It means that if they go clockwise around the sun they also spin clockwise

"on the fly" means while in progress or motion Generally refers to doing something without preperation

A story of John That would be a story about John

Refers to the amount of Elon's wealth. I guess used as an idiom in this situation to mean he was very wealthy.

Reads like a negative book review to me while seeming as though you may be trying to be positive. If I were to change it for what I think you are going for it would be She has a unique style of writing that puts me in the heart of the story. In addition, there are few actions that I find boring. There are a lot of descriptions and details that aren't important though. If this isn't what you're looking for comment. Generally I don't recommend starting a sentence with but. Also I don't necessarily love the sentences but I was trying to keep them as close as I could to your originals. Also when writing unless referring to location I would not use there's unless referring to location. There's the house. Even as such I'm not a fan myself.

Hrmm that's a tough one but I would do Any knowledge can be learned if you read more, write more, think more, and ask more often enough. I would use acquired instead of learned and inquire instead of ask though. Learned just doesn't seem to work and generally with knowledge English uses acquired. Personally inquire sounds better than ask to me but ask sounds okay. I do wish someone else would examine my sentence though as something is bothering me about it.

If it is with a wife or girlfriend some people will use date. Other than date though there really isn't a set noun for an informal meeting. Generally we just describe what we'll be doing such as "I'm going to go walking with a friend." If you want to be nonspecific something like "I'm going to meet someone"