Can I use "more" without comparing?
Like: Am I comparing when I say these phrases?
I need more coffee;
People need more love;
You need to be more silent;
Your examples are the compartive degree of much.
I need more coffee (than I have already drunk)
People need more love (than they are getting now)
In these cases you implictly comparing the amount needed with the amount already received, or the amount that is available.
The third example is the comparative degree of "silent", but is unusual because silent is not often used in a comparative degree.
Yes you can as you are not saying for example “I need coffee more than the other people here.”