Some of these are incorrect?

They are all wrong. All of your examples are incomplete thoughts, which cannot use a colon. Also, my questions as following is ungrammatical.

My suggestions are to… (incomplete thought, no colon)
My suggestions are as follows: … (complete thought, use colon)
My sugg

Thank you. If I were to be writing the suggestions that follows right below the sentence line, then it would be correct to write:

? My suggestions below:

No, it's not good grammar. It should be a complete sentence.

My suggestions are below:

Here are my suggestions:

Thanks. In writing, how many space is needed after : eg. Remember this: It is you who control the work, not the work that controls you.

chiachenThanks. In writing, how many space is needed after : eg. Remember this: It is you who control the work, not the work that controls you.

To make a boring story bearable, only one space is needed after a colon and a period. In the old days, when we used typewriters, two spaces were necessary for better readability. Some people still use two spaces, thoug

May I ask, they convey exactly the same meaning?
Remember : You control the work, (it is) not the work controls you. and Remember this: It is you who controls the work, not the work controls you.

chiachenMay I ask, they convey exactly the same meaning?
Remember : You control the work, (it is) not the work controls you. and Remember this: It is you who controls the work, not the work controls you.

Yes, but they are incorrect.

Remember: You control the work; the work doesn't control you.
Remember this: It is you

Is it correct: Spend the weekends with your family and on your hobbies.

chiachenIs it correct: Spend the weekends with your family and on your hobbies.

It's fine.

Thanks.