SHOULD

Should can be used after in case to emphasisSpecial importance or attention given to something. E.g.: All I wanna do is have some fun.e unlikelihood. This use is rather formalNot belonging to colloquial or everyday speech; official. E.g.: I demand that Mr Smith call the person on whom the committee has decided. or may even sound archaic to some speakers.

SHOULD

Should + perfectThe aspect expressing completion. E.g.: He’s finished university. infinitive can be used to emphasisSpecial importance or attention given to something. E.g.: All I wanna do is have some fun.e unlikelihood in the past. This use is rather formalNot belonging to colloquial or everyday speech; official. E.g.: I demand that Mr Smith call the person on whom the committee has decided. or may even sound archaic to some speakers.

With all persons shall can be used to emphasisSpecial importance or attention given to something. E.g.: All I wanna do is have some fun.e something which the speaker feels certain to happen or wants to happen.

I shall definitely give up smoking this year!
We shall win!
"We shall overcome!"

Instead of will here we can use may/might (certainty/uncertainty), may (permission), can (permission or ability) or must/should (obligation).

Dare/dare to means to have the courage or impudence to do something difficult or dangerous, or something you have no right to do.

The use of dare and dare to is similar to that of need and need to. Dare is a modal auxiliaryA helping verb used with main verbs to express mood, voice and tense. E.g.: I can't stand when I am disturbed. ("can", "am"), whereas in dare to "dare" functions as a main verbA verb that can express an action or state in itself. E.g.: John likes squash a lot. ("like").

Should + perfectThe aspect expressing completion. E.g.: He’s finished university. infinitive is used as a polite expressionA word or group of words used in a particular situation. E.g.: Good morning, at six, on the sofa of thanks on receiving a gift or a favour.

"I've brought some wine."
"Oh, you really shouldn't have!" 

The auxiliaryA helping verb used with main verbs to express mood, voice and tense. E.g.: I can't stand when I am disturbed. ("can", "am") may is used to express contrast.

You may be right, but that is no excuse for shouting like this. (Although you are right, that is...)

Try as somebody may (present reference) and try as somebody might (past reference) mean however hard I try/tried...